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5) #include "head.wmi" TITLE="Tor Project: FAQ" CHARSET="UTF-8"
6) <div id="content" class="clearfix">
7)   <div id="breadcrumbs">

8)     <a href="<page index>">Home &raquo; </a>

9)     <a href="<page docs/documentation>">Documentation &raquo; </a>
10)     <a href="<page docs/faq>">FAQ</a>
11)   </div>
12)   <div id="maincol">
13)     <!-- PUT CONTENT AFTER THIS TAG -->
14)     <h1>Tor FAQ</h1>

15)     <hr>

16) 

17)     <p>General questions:</p>
18)     <ul>
19)     <li><a href="#WhatIsTor">What is Tor?</a></li>

20)     <li><a href="#Torisdifferent">How is Tor different from other
21) proxies?</a></li>

22)     <li><a href="#CompatibleApplications">What programs can I use with
23)     Tor?</a></li>
24)     <li><a href="#WhyCalledTor">Why is it called Tor?</a></li>
25)     <li><a href="#Backdoor">Is there a backdoor in Tor?</a></li>

26)     <li><a href="#DistributingTor">Can I distribute Tor?</a></li>

27)     <li><a href="#SupportMail">How can I get support?</a></li>

28)     <li><a href="#Forum">Is there a Tor forum?</a></li>

29)     <li><a href="#WhySlow">Why is Tor so slow?</a></li>

30)     <li><a href="#FileSharing">How can I share files anonymously through Tor?
31)     </a></li>
32)     <li><a href="#OutboundPorts">Do I have to open all these outbound ports 
33)     on my firewall?</a></li>

34)     <li><a href="#Funding">What would The Tor Project do with more
35)     funding?</a></li>

36)     <li><a href="#IsItWorking">How can I tell if Tor is working, and that my 
37)     connections really are anonymized?</a></li>

38)     <li><a href="#FTP">How do I use my browser for ftp with Tor?</a></li>

39)     <li><a href="#Metrics">How many people use Tor? How many relays or
40)     exit nodes are there?</a></li>

41)     <li><a href="#SSLcertfingerprint">What are your SSL certificate

42)     fingerprints?</a></li>

43)     </ul>

44) 

45)     <p>Compilation and Installation:</p>
46)     <ul>
47)     <li><a href="#HowUninstallTor">How do I uninstall Tor?</a></li>
48)     <li><a href="#PGPSigs">What are these "sig" files on the download
49)     page?</a></li>

50)     <li><a href="#GetTor">Your website is blocked in my country. How
51)     do I download Tor?</a></li>

52)     <li><a href="#CompileTorWindows">How do I compile Tor under
53) Windows?</a></li>
54)     <li><a href="#VirusFalsePositives">Why does my Tor executable appear
55) to

56)     have a virus or spyware?</a></li>

57)     <li><a href="#LiveCD">Is there a LiveCD or other bundle that
58) includes Tor?</a></li>

59)     </ul>

60) 

61)     <p>Tor Browser Bundle:</p>
62)     <ul>

63) 

64)     <li><a href="#TBBFlash">Why can't I view videos on YouTube and other
65)     Flash-based sites?</a></li>

66)     <li><a href="#Ubuntu">I'm using Ubuntu and I can't start Tor Browser
67)     </a></li>

68)     <li><a href="#TBBSocksPort">I want to

69)     run another application through the Tor launched by Tor Browser

70)     Bundle.</a></li>

71)     <li><a href="#TBBPolipo">I need an HTTP proxy. Where did Polipo
72)     go?</a></li>

73)     <li><a href="#TBBOtherExtensions">Can I install other Firefox

74)     extensions? Which extensions should I avoid using?</a></li>

75)     <li><a href="#TBBJavaScriptEnabled">Why is NoScript configured to
76) allow JavaScript by default in the Tor Browser Bundle?  Isn't that
77) unsafe?</a></li>

78)     <li><a href="#TBBOtherBrowser">I want to use Chrome/IE/Opera/etc
79)     with Tor.</a></li>

80)     <li><a href="#TorbuttonOtherBrowser">Will Torbutton be available for other browsers?</a></li>

81)     <li><a href="#TBBCloseBrowser">I want to leave Tor Browser Bundle
82)     running but close the browser.</a></li>
83) 

84)     <li><a href="#GoogleCAPTCHA">Google makes me solve a CAPTCHA or

85) tells

86)     me I have spyware installed.</a></li>

87)     <li><a href="#ForeignLanguages">Why does Google show up in foreign 

88)     languages?</a></li>

89)     <li><a href="#GmailWarning">Gmail warns me that my account may have
90)     been compromised.</a></li>

91)     <li><a href="#NeedToUseAProxy">My internet connection requires an HTTP 
92)     or SOCKS Proxy</a></li>

93)     <li><a href="#CantSetProxy">What should I do if I can't set a proxy 
94)     with my application?</a></li>

95)     <li><a href="#WhereDidVidaliaGo">Where did the world map (Vidalia) 
96)     go?</a></li>
97)     <li><a href="#DisableJS">How do I disable JavaScript?</a></li>
98)     <li><a href="#VerifyDownload">How do I verify the download 
99)     (sha256sums.txt)?</a></li>
100)     <li><a href="#NewIdentityClosingTabs">Why does "New Identity" close 
101)     all my open tabs?</a></li>
102)     <li><a href="#ConfigureRelayOrBridge">How do I configure Tor as a relay 
103)     or bridge?</a></li>
104)     <li><a href="#Timestamps">Why are the file timestamps from 2000?</a></li>
105)     <li><a href="#SourceCode">Where is the source code for the bundle? How do 
106)     I verify a build?</a></li>

107)     </ul>
108) 
109)     <p>Advanced Tor usage:</p>

110)     <ul>
111)     <li><a href="#torrc">I'm supposed to "edit my torrc". What does
112)     that mean?</a></li>

113)     <li><a href="#Logs">How do I set up logging, or see Tor's

114)     logs?</a></li>

115)     <li><a href="#LogLevel">What log level should I use?</a></li>

116)     <li><a href="#DoesntWork">Tor is running, but it's not working
117)     correctly.</a></li>

118)     <li><a href="#TorCrash">My Tor keeps crashing.</a></li>

119)     <li><a href="#VidaliaPassword">Tor/Vidalia prompts for a password at
120)     start.</a></li>

121)     <li><a href="#ChooseEntryExit">Can I control which nodes (or
122) country)

123)     are used for entry/exit?</a></li>

124)     <li><a href="#FirewallPorts">My firewall only allows a few outgoing
125)     ports.</a></li>

126)     <li><a href="#DefaultExitPorts">Is there a list of default exit ports?</a></li>

127)     <li><a href="#WarningsAboutSOCKSandDNSInformationLeaks">I keep seeing 
128)     these warnings about SOCKS and DNS information leaks. Should I 
129)     worry?</a></li>

130)     <li><a href="#SocksAndDNS">How do I check if my application that uses 
131)     SOCKS is leaking DNS requests?</a></li>
132)     <li><a href="#DifferentComputer">I want to run my Tor client on a 
133)     different computer than my applications.</a></li>
134)     <li><a href="#ServerClient">Can I install Tor on a central server, and 
135)     have my clients connect to it?</a></li>
136)     <li><a href="#JoinTheNetwork">So I can just configure a nickname and 
137)     ORPort and join the network?</a></li>

138)     </ul>

139) 

140)     <p>Running a Tor relay:</p>
141)     <ul>

142) 
143)     <li><a href="#HowDoIDecide">How do I decide if I should run a relay?
144)     </a></li>

145)     <li><a href="#WhyIsntMyRelayBeingUsedMore">Why isn't my relay being 
146)     used more?</a></li>

147)     <li><a href="#IDontHaveAStaticIP">I don't have a static IP.</a></li>
148)     <li><a href="#ModemKeepsCrashing">My cable/dsl modem keeps crashing. 
149)     What's going on?</a></li>
150)     <li><a href="#PortscannedMore">Why do I get portscanned more often 
151)     when I run a Tor relay?</a></li>
152)     <li><a href="#MoreThanOneCPU">I have more than one CPU. Does this 
153)     help?</a></li>

154)     <li><a href="#HighCapacityConnection">How can I get Tor to fully 
155)     make use of my high capacity connection?</a></li>

156)     <li><a href="#RelayFlexible">How stable does my relay need to
157) be?</a></li>

158)     <li><a href="#BandwidthShaping">What bandwidth shaping options are 
159)     available to Tor relays?</a></li>
160)     <li><a href="#LimitTotalBandwidth">How can I limit the total amount 
161)     of bandwidth used by my Tor relay?</a></li>
162)     <li><a href="#ExitPolicies">I'd run a relay, but I don't want to deal

163)     with abuse issues.</a></li>
164)     <li><a href="#RelayOrBridge">Should I be a normal relay or bridge
165)     relay?</a></li>

166)     <li><a href="#UpgradeOrMove">I want to upgrade/move my relay. How do I 
167)     keep the same key?</a></li>

168)     <li><a href="#MultipleRelays">I want to run more than one
169) relay.</a></li>

170)     <li><a href="#NTService">How do I run my Tor relay as an NT service?
171)     </a></li>
172)     <li><a href="#VirtualServer">Can I run a Tor relay from my virtual server 
173)     account?</a></li>

174)     <li><a href="#WrongIP">My relay is picking the wrong IP address.</a></li>
175)     <li><a href="#BehindANAT">I'm behind a NAT/Firewall</a></li>

176)     <li><a href="#RelayMemory">Why is my Tor relay using so much memory?
177)     </a></li>
178)     <li><a href="#BetterAnonymity">Do I get better anonymity if I run a relay?
179)     </a></li>

180)     <li><a href="#RelayDonations">Can I donate for a relay rather than
181)     run my own?</a></li>

182)     </ul>

183) 

184)     <p>Tor hidden services:</p>
185)     <ul>
186)     <li><a href="#AccessHiddenServices">How do I access hidden services?</a></li>
187)     <li><a href="#ProvideAHiddenService">How do I provide a hidden service</a></li>
188)     </ul>

189) 

190)     <p>Development</p>
191)     <ul>
192)     <li><a href="#WhoIsResponsible">Who is responsible for Tor?</a></li>
193)     <li><a href="#VersionNumbers">What do these weird version numbers 
194)     mean?</a></li>
195)     <li><a href="#PrivateTorNetwork">How do I set up my own private
196)     Tor network?</a></li>
197)     <li><a href="#UseTorWithJava">How can I make my Java program use the 
198)     Tor network?</a></li>
199)     <li><a href="#WhatIsLibevent">What is Libevent?</a></li>
200)     <li><a href="#MyNewFeature">What do I need to do to get a new feature 
201)     into Tor?</a></li>
202)     </ul>
203) 

204)     <p>Anonymity and Security:</p>
205)     <ul>

206)     <li><a href="#WhatProtectionsDoesTorProvide">What protections does Tor 
207)     provide?</a></li>
208)     <li><a href="#CanExitNodesEavesdrop">Can exit nodes eavesdrop on 
209)     communications? Isn't that bad? </a></li>

210)     <li><a href="#AmITotallyAnonymous">So I'm totally anonymous if I use 
211)     Tor?</a></li>

212)     <li><a href="#ExitEnclaving">What is Exit Enclaving?</a></li>

213)     <li><a href="#KeyManagement">Tell me about all the keys Tor
214) uses.</a></li>

215)     <li><a href="#EntryGuards">What are Entry Guards?</a></li>

216)     <li><a href="#ChangePaths">How often does Tor change its paths?</a></li>

217)     <li><a href="#CellSize">Tor uses hundreds of bytes for every IRC line. I 
218)     can't afford that!</a></li>
219)     <li><a href="#OutboundConnections">Why does netstat show these outbound 
220)     connections?</a></li>
221)     <li><a href="#PowerfulBlockers">What about powerful blocking mechanisms
222)     </a></li>
223)     <li><a href="#RemotePhysicalDeviceFingerprinting">Does Tor resist 
224)     "remote physical device fingerprinting"?</a></li>

225)     <li><a href="#VPN">Is Tor like a VPN?</a></li>

226)     <li><a href="#Proxychains">Aren't 10 proxies (proxychains) better than 
227)     Tor with only 3 hops?</a></li>

228)     <li><a href="#AttacksOnOnionRouting">What attacks remain against onion 
229)     routing?</a></li>

230)     </ul>

231) 

232)     <p>Alternate designs that we don't do (yet):</p>
233)     <ul>
234)     <li><a href="#EverybodyARelay">You should make every Tor user be a
235)     relay.</a></li>

236)     <li><a href="#TransportIPnotTCP">You should transport all IP
237) packets,

238)     not just TCP packets.</a></li>

239)     <li><a href="#HideExits">You should hide the list of Tor relays,
240)     so people can't block the exits.</a></li>

241)     <li><a href="#ChoosePathLength">You should let people choose their path 
242)     length.</a></li>
243)     <li><a href="#SplitEachConnection">You should split each connection over 
244)     many paths.</a></li>
245)     <li><a href="#UnallocatedNetBlocks">Your default exit policy should block 
246)     unallocated net blocks too.</a></li>
247)     <li><a href="#BlockWebsites">Exit policies should be able to block 
248)     websites, not just IP addresses.</a></li>
249)     <li><a href="#BlockContent">You should change Tor to prevent users from 
250)     posting certain content.</a></li>

251)     <li><a href="#SendPadding">You should send padding so it's more secure.
252)     </a></li>
253)     <li><a href="#Steganography">You should use steganography to hide Tor 
254)     traffic.</a></li>

255)     <li><a href="#IPv6">Tor should support IPv6.</a></li>

256)     </ul>

257) 

258)     <p>Abuse:</p>

259)     <ul>

260)     <li><a href="#Criminals">Doesn't Tor enable criminals to do bad
261) things?</a></li>

262)     <li><a href="#RespondISP">How do I respond to my ISP about my exit
263)     relay?</a></li>

264)     <li><a href="#HelpPoliceOrLawyers">I have questions about
265)    a Tor IP address for a legal case.</a></li>

266)     </ul>

267) 

268)     <p>For other questions not yet on this version of the FAQ, see the
269) <a

270)     href="<wikifaq>">wiki FAQ</a> for now.</p>

271) 

272)     <hr>

273) 

274)     <a id="General"></a>

275) 

276)     <a id="WhatIsTor"></a>
277)     <h3><a class="anchor" href="#WhatIsTor">What is Tor?</a></h3>

278) 

279)     <p>
280)     The name "Tor" can refer to several different components.
281)     </p>

282) 

283)     <p>

284)     The Tor software is a program you can run on your computer that
285) helps keep
286)     you safe on the Internet. Tor protects you by bouncing your
287) communications

288)     around a distributed network of relays run by volunteers all around

289)     the world: it prevents somebody watching your Internet connection
290) from

291)     learning what sites you visit, and it prevents the sites you visit

292)     from learning your physical location. This set of volunteer relays
293) is
294)     called the Tor network. You can read more about how Tor works on the
295) <a

296)     href="<page about/overview>">overview page</a>.
297)     </p>

298) 

299)     <p>

300)     The Tor Project is a non-profit (charity) organization that
301) maintains

302)     and develops the Tor software.
303)     </p>

304) 

305)     <hr>

306) 

307)     <a id="Torisdifferent"></a>

308)     <h3><a class="anchor" href="#Torisdifferent">How is Tor different
309) from other proxies?</a></h3>
310)     <p>
311)     A typical proxy provider sets up a server somewhere on the Internet
312) and
313) allows you to use it to relay your traffic.  This creates a simple, easy
314) to
315) maintain architecture.  The users all enter and leave through the same
316) server.
317) The provider may charge for use of the proxy, or fund their costs
318) through
319) advertisements on the server.  In the simplest configuration, you don't
320) have to
321) install anything.  You just have to point your browser at their proxy
322) server.
323) Simple proxy providers are fine solutions if you do not want protections
324) for
325) your privacy and anonymity online and you trust the provider from doing
326) bad
327) things.  Some simple proxy providers use SSL to secure your connection
328) to them.
329) This may protect you against local eavesdroppers, such as those at a
330) cafe with

331) free wifi Internet.
332)     </p>
333)     <p>

334)     Simple proxy providers also create a single point of failure.  The
335) provider
336) knows who you are and where you browse on the Internet.  They can see
337) your
338) traffic as it passes through their server.  In some cases, they can even
339) see

340) inside your

341) encrypted traffic as they relay it to your banking site or to ecommerce
342) stores.

343) You have to trust the provider isn't doing any number of things, such as

344) watching your traffic, injecting their own advertisements into your
345) traffic

346) stream, and recording your personal details.

347)     </p>
348)     <p>

349)     Tor passes your traffic through at least 3 different servers before
350) sending
351) it on to the destination. Because there's a separate layer of encryption
352) for
353) each of the three relays, Tor does not modify, or even know, what you
354) are
355) sending into it.  It merely relays your traffic, completely encrypted
356) through
357) the Tor network and has it pop out somewhere else in the world,
358) completely
359) intact.  The Tor client is required because we assume you trust your
360) local
361) computer.  The Tor client manages the encryption and the path chosen
362) through
363) the network.  The relays located all over the world merely pass
364) encrypted

365) packets between themselves.</p>

366)     <p>
367)     <dl>

368)     <dt>Doesn't the first server see who I am?</dt><dd>Possibly. A bad
369) first of
370) three servers can see encrypted Tor traffic coming from your computer.
371) It
372) still doesn't know who you are and what you are doing over Tor.  It
373) merely sees
374) "This IP address is using Tor".  Tor is not illegal anywhere in the
375) world, so
376) using Tor by itself is fine.  You are still protected from this node
377) figuring

378) out who you are and where you are going on the Internet.</dd>

379)     <dt>Can't the third server see my traffic?</dt><dd>Possibly.  A bad
380) third
381) of three servers can see the traffic you sent into Tor.  It won't know
382) who sent

383) this traffic.  If you're using encryption, such as visiting a bank or

384) e-commerce website, or encrypted mail connections, etc, it will only
385) know the
386) destination.  It won't be able to see the data inside the traffic
387) stream.  You

388) are still protected from this node figuring out who you are and if using
389) encryption, what data you're sending to the destination.</dd>

390)     </dl>
391)     </p>

392) 

393)     <hr>

394) 

395)     <a id="CompatibleApplications"></a>

396)     <h3><a class="anchor" href="#CompatibleApplications">What programs
397) can I use with Tor?</a></h3>

398) 

399)     <p>

400)     If you want to use Tor with a web browser, we provide the Tor Browser 
401)     Bundle, which includes everything you need to browse the web safely using 
402)     Tor. If you want to use another web browser with Tor, see <a 
403)     href="#TBBOtherBrowser">Other web browsers</a>. 

404)     </p>
405)     <p>
406)     There are plenty of other programs you can use with Tor,
407)     but we haven't researched the application-level anonymity

408)     issues on all of them well enough to be able to recommend a safe

409)     configuration. Our wiki has a list of instructions for <a

410)     href="<wiki>doc/TorifyHOWTO">Torifying

411)     specific applications</a>.

412)     Please add to these lists and help us keep them accurate!
413)     </p>

414) 

415)     <hr>

416) 

417)     <a id="WhyCalledTor"></a>

418)     <h3><a class="anchor" href="#WhyCalledTor">Why is it called
419) Tor?</a></h3>

420) 

421)     <p>
422)     Because Tor is the onion routing network. When we were starting the
423)     new next-generation design and implementation of onion routing in
424)     2001-2002, we would tell people we were working on onion routing,
425)     and they would say "Neat. Which one?" Even if onion routing has
426)     become a standard household term, Tor was born out of the actual <a
427)     href="http://www.onion-router.net/">onion routing project</a> run by
428)     the Naval Research Lab.
429)     </p>

430) 

431)     <p>
432)     (It's also got a fine translation from German and Turkish.)
433)     </p>

434) 

435)     <p>

436)     Note: even though it originally came from an acronym, Tor is not
437) spelled

438)     "TOR". Only the first letter is capitalized. In fact, we can usually

439)     spot people who haven't read any of our website (and have instead
440) learned
441)     everything they know about Tor from news articles) by the fact that
442) they

443)     spell it wrong.
444)     </p>

445) 

446)     <hr>

447) 

448)     <a id="Backdoor"></a>

449)     <h3><a class="anchor" href="#Backdoor">Is there a backdoor in
450) Tor?</a></h3>

451) 

452)     <p>

453)     There is absolutely no backdoor in Tor. Nobody has asked us to put
454) one
455)     in, and we know some smart lawyers who say that it's unlikely that
456) anybody

457)     will try to make us add one in our jurisdiction (U.S.). If they do
458)     ask us, we will fight them, and (the lawyers say) probably win.
459)     </p>

460) 

461)     <p>
462)     We think that putting a backdoor in Tor would be tremendously

463)     irresponsible to our users, and a bad precedent for security
464) software

465)     in general. If we ever put a deliberate backdoor in our security
466)     software, it would ruin our professional reputations. Nobody would
467)     trust our software ever again — for excellent reason!
468)     </p>

469) 

470)     <p>
471)     But that said, there are still plenty of subtle attacks
472)     people might try. Somebody might impersonate us, or break into our

473)     computers, or something like that. Tor is open source, and you
474) should
475)     always check the source (or at least the diffs since the last
476) release)

477)     for suspicious things. If we (or the distributors) don't give you
478)     source, that's a sure sign something funny might be going on. You
479)     should also check the <a href="<page docs/verifying-signatures>">PGP
480)     signatures</a> on the releases, to make sure nobody messed with the
481)     distribution sites.
482)     </p>

483) 

484)     <p>
485)     Also, there might be accidental bugs in Tor that could affect your

486)     anonymity. We periodically find and fix anonymity-related bugs, so
487) make

488)     sure you keep your Tor versions up-to-date.
489)     </p>

490) 

491)     <hr>

492) 

493)     <a id="DistributingTor"></a>

494)     <h3><a class="anchor" href="#DistributingTor">Can I distribute
495) Tor?</a></h3>

496) 

497)     <p>
498)     Yes.
499)     </p>

500) 

501)     <p>

502)     The Tor software is <a href="https://www.fsf.org/">free
503) software</a>. This
504)     means we give you the rights to redistribute the Tor software,
505) either
506)     modified or unmodified, either for a fee or gratis. You don't have
507) to

508)     ask us for specific permission.
509)     </p>

510) 

511)     <p>

512)     However, if you want to redistribute the Tor software you must
513) follow our

514)     <a href="<gitblob>LICENSE">LICENSE</a>.

515)     Essentially this means that you need to include our LICENSE file
516) along

517)     with whatever part of the Tor software you're distributing.
518)     </p>

519) 

520)     <p>

521)     Most people who ask us this question don't want to distribute just
522) the

523)     Tor software, though. They want to distribute the <a

524)     href="<page projects/torbrowser>">Tor Browser</a>. This includes <a

525)     href="https://www.mozilla.org/en-US/firefox/all-aurora.html">Mozilla
526)     Aurora</a> and <a href="<page projects/vidalia>">Vidalia</a>.

527)     You will need to follow the licenses for those programs
528)     as well. Both of them are distributed under the <a
529)     href="https://www.fsf.org/licensing/licenses/gpl.html">GNU General

530)     Public License</a>. The simplest way to obey their licenses is
531)     to include the source code for these programs everywhere you
532)     include the bundles themselves. Look for "source" packages on
533)     the <a href="<page projects/vidalia>">Vidalia page</a> and <a
534)     href="https://www.mozilla.org/en-US/firefox/all-aurora.html">Mozilla
535)     Aurora</a> pages.

536)     </p>

537) 

538)     <p>

539)     Also, you should make sure not to confuse your readers about what
540) Tor is,
541)     who makes it, and what properties it provides (and doesn't provide).
542) See
543)     our <a href="<page docs/trademark-faq>">trademark FAQ</a> for
544) details.

545)     </p>

546) 

547)     <p>
548)     Lastly, you should realize that we release new versions of the
549)     Tor software frequently, and sometimes we make backward incompatible

550)     changes. So if you distribute a particular version of the Tor
551) software, it
552)     may not be supported — or even work — six months later.
553) This

554)     is a fact of life for all security software under heavy development.
555)     </p>

556) 

557)     <hr>

558) 

559)     <a id="SupportMail"></a>

560)     <h3><a class="anchor" href="#SupportMail">How can I get
561) support?</a></h3>

562) 

563)     <p>Your best bet is to first try the following:</p>

564)     <ol>
565)     <li>Read through this <a href="<page docs/faq>">FAQ</a>.</li>

566)     <li>Read through the <a href="<page
567) docs/documentation>">documentation</a>.</li>

568)     <li>Read through the <a

569) 
570) href="https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-talk">
571) tor-talk

572)     archives</a> and see if your question is already answered.</li>

573)     <li>Join our <a href="ircs://irc.torproject.org#tor">irc channel</a>
574) and

575)     state the issue and wait for help.</li>

576)     <li>Send an email to <a

577) 
578) href="mailto:help@rt.torproject.org">help@rt.torproject.org</a>.</li>
579)     <li>If all else fails, try <a href="<page about/contact>">contacting
580) us</a> directly.</li>

581)     </ol>

582) 

583)     <p>If you find your answer, please stick around on the IRC channel
584) or the

585)     mailing list to help others who were once in your position.</p>

586) 

587)     <hr>

588) 

589)     <a id="Forum"></a>
590)     <h3><a class="anchor" href="#Forum">Is there a Tor forum?</a></h3>
591) 

592)     <p>We have a <a href="https://tor.stackexchange.com/">StackExchange 

593)     page</a> that is currently in public beta.

594)     </p>
595) 
596)     <hr>
597) 

598)     <a id="WhySlow"></a>
599)     <h3><a class="anchor" href="#WhySlow">Why is Tor so slow?</a></h3>

600) 

601)     <p>
602)     There are many reasons why the Tor network is currently slow.
603)     </p>

604) 

605)     <p>

606)     Before we answer, though, you should realize that Tor is never going
607) to
608)     be blazing fast. Your traffic is bouncing through volunteers'
609) computers
610)     in various parts of the world, and some bottlenecks and network
611) latency

612)     will always be present. You shouldn't expect to see university-style
613)     bandwidth through Tor.
614)     </p>

615) 

616)     <p>

617)     But that doesn't mean that it can't be improved. The current Tor
618) network
619)     is quite small compared to the number of people trying to use it,
620) and
621)     many of these users don't understand or care that Tor can't
622) currently

623)     handle file-sharing traffic load.
624)     </p>

625) 

626)     <p>
627)     For the much more in-depth answer, see <a

628)     href="<blog>why-tor-is-slow">Roger's blog

629)     post on the topic</a>, which includes both a detailed PDF and a
630) video

631)     to go with it.
632)     </p>

633) 

634)     <p>
635)     What can you do to help?
636)     </p>

637) 

638)     <ul>

639) 

640)     <li>

641)     <a href="<page docs/tor-doc-relay>">Configure your Tor to relay
642) traffic
643)     for others</a>. Help make the Tor network large enough that we can
644) handle

645)     all the users who want privacy and security on the Internet.
646)     </li>

647) 

648)     <li>

649)     <a href="<page projects/vidalia>">Help us make Tor more usable</a>.
650) We

651)     especially need people to help make it easier to configure your Tor
652)     as a relay. Also, we need help with clear simple documentation to
653)     walk people through setting it up.
654)     </li>

655) 

656)     <li>

657)     There are some bottlenecks in the current Tor network. Help us
658) design
659)     experiments to track down and demonstrate where the problems are,
660) and

661)     then we can focus better on fixing them.
662)     </li>

663) 

664)     <li>
665)     Tor needs some architectural changes too. One important change is to

666)     start providing <a href="#EverybodyARelay">better service to people
667) who
668)     relay traffic</a>. We're working on this, and we'll finish faster if
669) we

670)     get to spend more time on it.
671)     </li>

672) 

673)     <li>

674)     Help do other things so we can do the hard stuff. Please take a
675) moment
676)     to figure out what your skills and interests are, and then <a
677) href="<page

678)     getinvolved/volunteer>">look at our volunteer page</a>.
679)     </li>

680) 

681)     <li>

682)     Help find sponsors for Tor. Do you work at a company or government
683) agency

684)     that uses Tor or has a use for Internet privacy, e.g. to browse the

685)     competition's websites discreetly, or to connect back to the home
686) servers
687)     when on the road without revealing affiliations? If your
688) organization has
689)     an interest in keeping the Tor network working, please contact them
690) about
691)     supporting Tor. Without sponsors, Tor is going to become even
692) slower.

693)     </li>

694) 

695)     <li>
696)     If you can't help out with any of the above, you can still help out

697)     individually by <a href="<page donate/donate>">donating a bit of
698) money to the

699)     cause</a>. It adds up!
700)     </li>

701) 

702)     </ul>

703) 

704)     <hr>

705) 

706)     <a id="FileSharing"></a>

707)     <h3><a class="anchor" href="#FileSharing">How can I share files 
708)     anonymously through Tor?</a></h3>

709) 
710)     <p>

711)     File sharing (peer-to-peer/P2P) is widely unwanted in the Tor network, 
712)     and exit nodes are configured to block file sharing traffic by default. 
713)     Tor is not really designed for it, and file sharing through Tor slows 
714)     down everyone's browsing. Also, Bittorrent over Tor <a 
715)     href="https://blog.torproject.org/blog/bittorrent-over-tor-isnt-good-idea">
716)     is not anonymous</a>!

717)     </p>
718) 
719)     <hr>
720) 

721)     <a id="Funding"></a>

722)     <h3><a class="anchor" href="#Funding">What would The Tor Project do
723) with more funding?</a></h3>

724) 

725)     <p>

726)     The Tor network's <a

727) 
728) href="https://metrics.torproject.org/network.html#networksize">several

729)     thousand</a> relays push <a
730)     href="https://metrics.torproject.org/network.html#bandwidth">over
731)     1GB per second on average</a>. We have <a

732) 
733) href="https://metrics.torproject.org/users.html#direct-users">several

734)     hundred thousand daily users</a>. But the Tor network is not yet
735)     self-sustaining.

736)     </p>

737) 

738)     <p>

739)     There are six main development/maintenance pushes that need
740) attention:

741)     </p>

742) 

743)     <ul>

744) 

745)     <li>
746)     Scalability: We need to keep scaling and decentralizing the Tor
747)     architecture so it can handle thousands of relays and millions of

748)     users. The upcoming stable release is a major improvement, but
749) there's

750)     lots more to be done next in terms of keeping Tor fast and stable.
751)     </li>

752) 

753)     <li>

754)     User support: With this many users, a lot of people are asking
755) questions
756)     all the time, offering to help out with things, and so on. We need
757) good
758)     clean docs, and we need to spend some effort coordinating
759) volunteers.

760)     </li>

761) 

762)     <li>

763)     Relay support: the Tor network is run by volunteers, but they still
764) need

765)     attention with prompt bug fixes, explanations when things go wrong,

766)     reminders to upgrade, and so on. The network itself is a commons,
767) and
768)     somebody needs to spend some energy making sure the relay operators
769) stay
770)     happy. We also need to work on stability on some platforms —
771) e.g.,

772)     Tor relays have problems on Win XP currently.

773)     </li>

774) 

775)     <li>

776)     Usability: Beyond documentation, we also need to work on usability
777) of the
778)     software itself. This includes installers, clean GUIs, easy
779) configuration
780)     to interface with other applications, and generally automating all
781) of
782)     the difficult and confusing steps inside Tor. We've got a start on
783) this
784)     with the <a href="<page projects/vidalia>">Vidalia GUI</a>, but much
785) more work

786)     remains — usability for privacy software has never been easy.
787)     </li>

788) 

789)     <li>
790)     Incentives: We need to work on ways to encourage people to configure
791)     their Tors as relays and exit nodes rather than just clients.

792)     <a href="#EverybodyARelay">We need to make it easy to become a
793) relay,

794)     and we need to give people incentives to do it.</a>
795)     </li>

796) 

797)     <li>
798)     Research: The anonymous communications field is full
799)     of surprises and gotchas. In our copious free time, we
800)     also help run top anonymity and privacy conferences like <a
801)     href="http://petsymposium.org/">PETS</a>. We've identified a set of

802)     critical <a href="<page getinvolved/volunteer>#Research">Tor
803) research questions</a>
804)     that will help us figure out how to make Tor secure against the
805) variety of
806)     attacks out there. Of course, there are more research questions
807) waiting

808)     behind these.
809)     </li>

810) 

811)     </ul>

812) 

813)     <p>
814)     We're continuing to move forward on all of these, but at this rate

815)     <a href="#WhySlow">the Tor network is growing faster than the
816) developers

817)     can keep up</a>.

818)     Now would be an excellent time to add a few more developers to the
819) effort

820)     so we can continue to grow the network.
821)     </p>

822) 

823)     <p>
824)     We are also excited about tackling related problems, such as
825)     censorship-resistance.
826)     </p>

827) 

828)     <p>

829)     We are proud to have <a href="<page about/sponsors>">sponsorship and
830) support</a>
831)     from the Omidyar Network, the International Broadcasting Bureau,
832) Bell
833)     Security Solutions, the Electronic Frontier Foundation, several
834) government

835)     agencies and research groups, and hundreds of private contributors.
836)     </p>

837) 

838)     <p>

839)     However, this support is not enough to keep Tor abreast of changes
840) in the
841)     Internet privacy landscape. Please <a href="<page
842) donate/donate>">donate</a>
843)     to the project, or <a href="<page about/contact>">contact</a> our
844) executive

845)     director for information on making grants or major donations.
846)     </p>

847) 

848)     <hr>
849) 

850)      <a id="OutboundPorts"></a>

851)     <h3><a class="anchor" href="#OutboundPorts">Do I have to open all these 
852)     outbound ports on my firewall?</a></h3>

853) 
854)     <p>

855)     Tor may attempt to connect to any port that is advertised in the 
856)     directory as an ORPort (for making Tor connections) or a DirPort (for 
857)     fetching updates to the directory). There are a variety of these ports, 
858)     but many of them are running on 80, 443, 9001, and 9030.

859)     </p>
860)     <p>

861)     So as a client, you could probably get away with opening only those four 
862)     ports. Since Tor does all its connections in the background, it will retry 
863)     ones that fail, and hopefully you'll never have to know that it failed, as 
864)     long as it finds a working one often enough. However, to get the most 
865)     diversity in your entry nodes -- and thus the most security -- as well as 
866)     the most robustness in your connectivity, you'll want to let it connect 
867)     to all of them.

868)     </p>
869)     <p>

870)     If you really need to connect to only a small set of ports, see the FAQ 

871)     entry on <a href="#FirewallPorts">firewalled ports</a>.

872)     </p>
873)     <p>

874)     Note that if you're running Tor as a relay, you must allow outgoing 
875)     connections to every other relay and to anywhere your exit policy 
876)     advertises that you allow. The cleanest way to do that is simply to allow 
877)     all outgoing connections at your firewall. If you don't, clients will try 
878)     to use these connections and things won't work. 

879)     </p>
880)     
881)     <hr>
882)     
883)     <a id="IsItWorking"></a>

884)     <h3><a class="anchor" href="#IsItWorking">How can I tell if Tor is 
885)     working, and that my connections really are anonymized?</a></h3>

886) 
887)     <p>

888)     There are sites you can visit that will tell you if you appear to be 
889)     coming through the Tor network. Try the <a href="https://check.torproject.org">
890)     Tor Check</a> site and see whether it thinks you are using Tor or not.

891)     </p>
892)     <p>

893)     If that site is down, you can still test, but it will involve more effort. 
894)     Sites like <a href="http://ipid.shat.net">http://ipid.shat.net</a> and 
895)     <a href="http://www.showmyip.com/">http://www.showmyip.com/</a> will tell 
896)     you what your IP address appears to be, but you'll need to know your 
897)     current IP address so you can compare and decide whether you're using Tor 
898)     correctly.

899)     </p>
900)     <p>

901)     To learn your IP address on OS X, Linux, BSD, etc, run "ifconfig". On 
902)     Windows, go to the Start menu, click Run and enter "cmd". At the command 
903)     prompt, enter "ipconfig /a".

904)     </p>
905)     <p>

906)     If you are behind a NAT or firewall, though, your IP address will be 
907)     within the range of 10.XXX.XXX.XXX, 192.168.XXX.XXX, or 172.16.XXX.XXX - 
908)     172.31.XXX.XXX, which is not your public IP address. In this case, you 
909)     should check your IP address with one of the sites above without using 
910)     Tor, and then check again using Tor to see whether your IP address has 
911)     changed. 

912)     </p>
913)     
914)     <hr>
915)     
916)     <a id="FTP"></a>
917)     <h3><a class="anchor" href="#FTP">How do I use my browser for ftp with Tor?
918)     </a></h3>
919) 

920)     <p>

921)     Use the <a href="https://torproject.org/projects/torbrowser.html">Tor 
922)     Browser Bundle</a>. If you want a separate application for an 

923)     ftp client, we've heard good things about  FileZilla for Windows. You can 
924)     configure it to point to Tor as a "socks4a" proxy on "localhost" port 
925)     "9050". 
926)     </p>

927)     <hr>
928)     

929)     <a id="Metrics"></a>

930)     <h3><a class="anchor" href="#Metrics">How many people use Tor? How

931)     many relays or exit nodes are there?</a></h3>

932) 

933)     <p>
934)     All this and more about measuring Tor can be found at the <a

935)     href="https://metrics.torproject.org/">Tor Metrics Portal</a>.</p>

936)     <hr>

937) 

938)     <a id="SSLcertfingerprint"></a>

939)     <h3><a class="anchor" href="#SSLcertfingerprint">What are the SSL 
940)     certificate fingerprints for Tor's various websites?</a></h3>

941)     <p>

942)     <pre>

943)     *.torproject.org SSL certificate from Digicert:

944)     The serial number is:

945) 06:DE:97:E5:1D:C3:9D:C2:64:8D:AC:72:DD:41:01:FC
946)     The SHA-1 fingerprint is: 1f9d306e8bfccfcb03981a71a27a9f5d1e0876ce

947)     The SHA-256 fingerprint is:

948) 3613d2b22a750094760c41ad19db52a4f05bdea80172e2578761ad967f7ed9aa

949) 

950)     blog.torproject.org SSL certificate from RapidSSL:

951)     The serial number is: 00:EF:A3
952)     The SHA-1 fingerprint is: 50af43db8438e67f305a3257d8ef198e8c42f13f

953)     </pre>

954)     </p>
955)     <hr>
956) 

957)     <a id="HowUninstallTor"></a>

958)     <h3><a class="anchor" href="#HowUninstallTor">How do I uninstall
959) Tor?</a></h3>
960) 
961)     <p>
962)     Tor Browser does not install itself in the classic sense of
963) applications. You just simply delete the folder or directory named "Tor
964) Browser" and it is removed from your system.
965)     </p>

966) 

967)     <p>

968)     If this is not related to Tor Browser, uninstallation depends
969) entirely on how you installed it and which operating system you
970)     have. If you installed a package, then hopefully your package has a
971) way to

972)     uninstall itself. The Windows packages include uninstallers. 

973)     </p>

974) 

975)     <p>
976)     For Mac OS X, follow the <a
977)     href="<page docs/tor-doc-osx>#uninstall">uninstall directions</a>.
978)     </p>

979) 

980)     <p>

981)     If you installed by source, I'm afraid there is no easy uninstall
982) method. But
983)     on the bright side, by default it only installs into /usr/local/ and
984) it should

985)     be pretty easy to notice things there.
986)     </p>

987) 

988)     <hr>

989) 

990)     <a id="PGPSigs"></a>

991)     <h3><a class="anchor" href="#PGPSigs">What are these "sig" files on
992) the download page?</a></h3>

993) 

994)     <p>

995)     These are PGP signatures, so you can verify that the file you've
996) downloaded is

997)     exactly the one that we intended you to get.
998)     </p>

999) 

1000)     <p>
1001)     Please read the <a

1002)     href="<page docs/verifying-signatures>">verifying signatures</a>
1003) page for details.

1004)     </p>

1005) 

1006) <hr>
1007) 
1008) <a id="GetTor"></a>
1009) <h3><a class="anchor" href="#GetTor">Your website is blocked in my
1010) country. How do I download Tor?</a></h3>
1011) 
1012) <p>
1013) Some government or corporate firewalls censor connections to Tor's
1014) website. In those cases, you have three options. First, get it from

1015) a friend &mdash; the <a href="<page projects/torbrowser>">Tor Browser

1016) Bundle</a> fits nicely on a USB key. Second, find the <a

1017) href="https://encrypted.google.com/search?q=tor+mirrors">google
1018) cache</a>

1019) for the <a href="<page getinvolved/mirrors>">Tor mirrors</a> page
1020) and see if any of those copies of our website work for you. Third,
1021) you can download Tor via email: log in to your Gmail account and mail

1022) '<tt>gettor@gettor.torproject.org</tt>'. If you include the word 'help'

1023) in the body of the email, it will reply with instructions. Note that
1024) only a few webmail providers are supported, since they need to be able
1025) to receive very large attachments.
1026) </p>
1027) 
1028) <p>

1029) Be sure to <a href="<page docs/verifying-signatures>">verify the
1030) signature</a>

1031) of any package you download, especially when you get it from somewhere
1032) other than our official HTTPS website.

1033) </p>
1034) 
1035) <hr>

1036) 

1037)     <a id="CompileTorWindows"></a>

1038)     <h3><a class="anchor" href="#CompileTorWindows">How do I compile Tor
1039) under Windows?</a></h3>

1040) 

1041)     <p>

1042)     Try following the steps at <a
1043) href="<gitblob>doc/tor-win32-mingw-creation.txt">

1044)     tor-win32-mingw-creation.txt</a>.
1045)     </p>

1046) 

1047)     <p>
1048)     (Note that you don't need to compile Tor yourself in order to use

1049)     it. Most people just use the packages available on the <a
1050) href="<page

1051)     download/download>">download page</a>.)
1052)     </p>

1053) 

1054)     <hr>

1055) 

1056)     <a id="VirusFalsePositives"></a>

1057)     <h3><a class="anchor" href="#VirusFalsePositives">Why does my Tor
1058) executable appear to have a virus or spyware?</a></h3>

1059) 

1060)     <p>

1061)     Sometimes, overzealous Windows virus and spyware detectors trigger
1062) on some
1063)     parts of the Tor Windows binary. Our best guess is that these are
1064) false
1065)     positives — after all, the anti-virus and anti-spyware
1066) business is just a
1067)     guessing game anyway. You should contact your vendor and explain
1068) that you have
1069)     a program that seems to be triggering false positives. Or pick a
1070) better vendor.

1071)     </p>

1072) 

1073)     <p>
1074)     In the meantime, we encourage you to not just take our word for

1075)     it. Our job is to provide the source; if you're concerned, please do
1076) <a

1077)     href="#CompileTorWindows">recompile it yourself</a>.
1078)     </p>

1079) 

1080)     <hr>

1081) 

1082)     <a id="LiveCD"></a>

1083)     <h3><a class="anchor" href="#LiveCD">Is there a LiveCD or other
1084) bundle that includes Tor?</a></h3>

1085) 

1086)     <p>

1087)     Yes.  Use <a href="https://tails.boum.org/">The Amnesic Incognito

1088)     Live System</a> or <a href="<page projects/torbrowser>">the Tor
1089) Browser

1090)     Bundle</a>.

1091)     </p>

1092) 
1093) <hr>
1094) 

1095) <a id="TBBFlash"></a>

1096) <h3><a class="anchor" href="#TBBFlash">Why can't I view videos on
1097) YouTube

1098) and other Flash-based sites?</a></h3>

1099) 
1100) <p>

1101) YouTube and similar sites require third party browser plugins such as Flash.
1102) Plugins operate independently from Firefox and can perform
1103) activity on your computer that ruins your anonymity. This includes
1104) but is not limited to: <a href="http://decloak.net">completely disregarding
1105) proxy settings</a>, querying your <a

1106) href="http://forums.sun.com/thread.jspa?threadID=5162138&messageID=9618376">
1107) local IP address</a>, and <a

1108) href="http://epic.org/privacy/cookies/flash.html">storing their own
1109) cookies</a>. It is possible to use a LiveCD solution such as

1110) or <a href="https://tails.boum.org/">The Amnesic Incognito Live System</a> 
1111) that creates a secure, transparent proxy to protect you from proxy bypass, 
1112) however issues with local IP address discovery and Flash cookies still remain. 
1113) </p>

1114) 
1115) <p>

1116) <a href="https://www.youtube.com/html5">YouTube offers experimental HTML5 video
1117) support</a> for many of their videos. You can use their Advanced Search to

1118) find HTML5 videos.
1119) </p>
1120) 

1121) <hr>
1122) 

1123) <a id="Ubuntu"></a>
1124) <h3><a class="anchor" href="#Ubuntu">
1125) I'm using Ubuntu and I can't start Tor Browser</a></h3>
1126) <p>

1127) Ubuntu prevents its users from executing shell scripts by clicking them, 
1128) even when the file permissions are set correctly. For now you need to 
1129) start the Tor Browser from the command line by running </p>

1130) <pre>
1131) ./start-tor-browser
1132) </pre>
1133) <p>
1134) from inside the Tor Browser directory.
1135) </p>
1136) 
1137) <hr>
1138) 

1139) <a id="TBBSocksPort"></a>

1140) <h3><a class="anchor" href="#TBBSocksPort">

1141) I want to run another application through the Tor launched by Tor

1142) Browser Bundle.</a></h3>

1143) 
1144) <p>

1145) Typically Tor listens for Socks connections on port 9050. TBB listens

1146) on port 9150.

1147) The goal is to avoid conflicting with a "system" Tor install,

1148) so you can run a system Tor and TBB at the same time. We're <a
1149) href="https://trac.torproject.org/projects/tor/ticket/3948">working on
1150) a feature</a> where Tor will try the usual ports first and then back

1151) off to a random choice if they're already in use.

1152) </p>
1153) 
1154) <hr>
1155) 
1156) <a id="TBBPolipo"></a>
1157) <h3><a class="anchor" href="#TBBPolipo">I need an HTTP proxy. Where did
1158) Polipo go?</a></h3>
1159) 
1160) <p>
1161) In the past, Tor bundles included an HTTP proxy like Privoxy or Polipo,
1162) solely to work around a bug in Firefox that was finally fixed in Firefox
1163) 6. Now you don't need a separate HTTP proxy to use Tor, and in fact
1164) leaving it out makes you safer because Torbutton has better control over
1165) Firefox's interaction with websites.
1166) </p>
1167) 
1168) <p>
1169) If you are trying to use some external application with Tor, step zero

1170) should be to <a href="<page download/download>#warning">reread the set

1171) of warnings</a> for ways you can screw up. Step one should be to try

1172) to use a Socks proxy rather than an http proxy — Tor runs a Socks

1173) proxy on port 9050 on Windows, or <a href="#TBBSocksPort">see above</a>
1174) for OSX and Linux.
1175) </p>
1176) 
1177) <p>

1178) If that fails, feel free to install <a

1179) href="http://www.privoxy.org/">privoxy</a>.
1180) However, please realize that this approach is not recommended for novice
1181) users. Privoxy has an <a
1182) href="http://www.privoxy.org/faq/misc.html#TOR">example
1183) configuration</a> of Tor and Privoxy.

1184) </p>
1185) 
1186) <hr>
1187) 

1188) <a id="TBBOtherExtensions"></a>
1189) <h3><a class="anchor" href="#TBBOtherExtensions">Can I install other
1190) Firefox extensions?</a></h3>
1191) 
1192) <p>

1193) The Tor Browser is free software, so there is nothing preventing you from 
1194) modifying it any way you like. However, we do not recommend installing any 
1195) additional Firefox add-ons with the Tor Browser Bundle. Add-ons can break 
1196) your anonymity in a number of ways, including browser fingerprinting and 
1197) bypassing proxy settings.

1198) </p>

1199) <p>

1200) Some people have suggested we include ad-blocking software or 
1201) anti-tracking software with the Tor Browser Bundle. Right now, we do not 
1202) think that's such a good idea. The Tor Browser Bundle aims to provide 
1203) sufficient privacy that additional add-ons to stop ads and trackers are 
1204) not necessary. Using add-ons like these may cause some sites to break, which 
1205) <a href="https://www.torproject.org/projects/torbrowser/design/#philosophy">
1206) we don't want to do</a>. Additionally, maintaining a list of "bad" sites that 
1207) should be black-listed provides another opportunity to uniquely fingerprint 
1208) users. 

1209) </p>

1210) 

1211) <hr>
1212) 

1213) <a id="TBBJavaScriptEnabled"></a>

1214) <a id="TBBCanIBlockJS"></a>

1215) <h3><a class="anchor" href="#TBBJavaScriptEnabled">Why is NoScript
1216) configured to allow JavaScript by default in the Tor Browser Bundle?
1217) Isn't that unsafe?</a></h3>

1218) 
1219) <p>
1220) We configure NoScript to allow JavaScript by default in the Tor
1221) Browser Bundle because many websites will not work with JavaScript
1222) disabled.  Most users would give up on Tor entirely if a website
1223) they want to use requires JavaScript, because they would not know
1224) how to allow a website to use JavaScript (or that enabling
1225) JavaScript might make a website work).
1226) </p>
1227) 

1228) <p>
1229) There's a tradeoff here. On the one hand, we should leave
1230) JavaScript enabled by default so websites work the way
1231) users expect. On the other hand, we should disable JavaScript
1232) by default to better protect against browser vulnerabilities (<a

1233) href="https://blog.torproject.org/blog/tor-security-advisory-old-tor-browser-bundles-vulnerable">
1234) not just a theoretical concern!</a>). But there's a third issue: websites

1235) can easily determine whether you have allowed JavaScript for them,
1236) and if you disable JavaScript by default but then allow a few websites
1237) to run scripts (the way most people use NoScript), then your choice of
1238) whitelisted websites acts as a sort of cookie that makes you recognizable
1239) (and distinguishable), thus harming your anonymity.
1240) </p>

1241) 
1242) <p>

1243) Ultimately, we want the default Tor bundles to use
1244) a combination of firewalls (like the iptables rules
1245) in <a href="https://tails.boum.org/">Tails</a>) and <a
1246) href="https://trac.torproject.org/projects/tor/ticket/7680">sandboxes</a>
1247) to make JavaScript not so scary. In
1248) the shorter term, TBB 3.0 will hopefully <a
1249) href="https://trac.torproject.org/projects/tor/ticket/9387">allow users
1250) to choose their JavaScript settings more easily</a> &mdash; but the
1251) partitioning concern will remain.

1252) </p>
1253) 
1254) <p>

1255) Until we get there, feel free to leave JavaScript on or off depending
1256) on your security, anonymity, and usability priorities.

1257) </p>
1258) 
1259) <hr>
1260) 

1261) <a id="TBBOtherBrowser"></a>
1262) <h3><a class="anchor" href="#TBBOtherBrowser">I want to use
1263) Chrome/IE/Opera/etc with Tor.</a></h3>
1264) 
1265) <p>
1266) Unfortunately, Torbutton only works with Firefox right now, and without
1267) <a href="https://www.torproject.org/torbutton/en/design/">Torbutton's
1268) extensive privacy fixes</a> there are many ways for websites or other

1269) attackers to recognize you, track you back to your IP address, and so
1270) on.

1271) In short, using any browser besides Tor Browser Bundle with Tor is a
1272) really bad idea.
1273) </p>
1274) 
1275) <p>
1276) We're working with the Chrome team to <a

1277) href="https://blog.torproject.org/blog/google-chrome-incognito-mode-tor-
1278) and-fingerprinting">fix
1279) some bugs and missing APIs in Chrome</a> so it will be possible to write
1280) a
1281) Torbutton for Chrome. No support for any other browser is on the
1282) horizon.

1283) </p>
1284) 
1285) <hr>
1286) 

1287) <a id="TorbuttonOtherBrowser"></a>

1288) <h3><a class="anchor" href="#TorbuttonOtherBrowser">

1289) Will ​Torbutton be available for other browsers?</a></h3>

1290) 
1291) <p>

1292)  We don't support IE, Opera or Safari and never plan to. There are too many ways that your privacy can go wrong with those browsers, and because of their closed design it is really hard for us to do anything to change these privacy problems.

1293) </p>
1294) <p>

1295) We are working with the Chrome people to modify Chrome's internals so that we can eventually support it. But for now, Firefox is the only safe choice. 

1296) </p>
1297) 

1298) <hr>

1299) 

1300) <a id="TBBCloseBrowser"></a>

1301) <h3><a class="anchor" href="#TBBCloseBrowser">I want to leave Tor
1302) Browser

1303) Bundle running but close the browser.</a></h3>
1304) 
1305) <p>
1306) We're working on a way to make this possible on all platforms. Please
1307) be patient.
1308) </p>
1309) 
1310) <hr>
1311) 

1312) <a id="GoogleCAPTCHA"></a>
1313) <h3><a class="anchor" href="#GoogleCAPTCHA">Google makes me solve a
1314) CAPTCHA or tells me I have spyware installed.</a></h3>

1315) 
1316) <p>
1317) This is a known and intermittent problem; it does not mean that Google
1318) considers Tor to be spyware.
1319) </p>
1320) 
1321) <p>

1322) When you use Tor, you are sending queries through exit relays that are
1323) also

1324) shared by thousands of other users. Tor users typically see this message

1325) when many Tor users are querying Google in a short period of time.
1326) Google

1327) interprets the high volume of traffic from a single IP address (the exit
1328) relay you happened to pick) as somebody trying to "crawl" their website,
1329) so it slows down traffic from that IP address for a short time.
1330) </p>
1331) <p>
1332) An alternate explanation is that Google tries to detect certain
1333) kinds of spyware or viruses that send distinctive queries to Google
1334) Search. It notes the IP addresses from which those queries are received
1335) (not realizing that they are Tor exit relays), and tries to warn any
1336) connections coming from those IP addresses that recent queries indicate
1337) an infection.
1338) </p>
1339) 
1340) <p>

1341) To our knowledge, Google is not doing anything intentionally
1342) specifically

1343) to deter or block Tor use. The error message about an infected machine
1344) should clear up again after a short time.
1345) </p>
1346) 
1347) <p>
1348) Torbutton 1.2.5 (released in mid 2010) detects Google captchas and can
1349) automatically redirect you to a more Tor-friendly search engine such as

1350) DuckDuckGo, ixquick, or Bing.

1351) </p>
1352) 
1353) <hr />
1354) 

1355) <a id="ForeignLanguages"></a>
1356) <h3><a class="anchor" href="#ForeignLanguages">
1357) Why does Google show up in foreign languages?</a></h3>
1358) 
1359) <p>

1360)  Google uses "geolocation" to determine where in the world you are, so it 
1361)  can give you a personalized experience. This includes using the language 
1362)  it thinks you prefer, and it also includes giving you different results 
1363)  on your queries.

1364) </p>
1365) <p>

1366) If you really want to see Google in English you can click the link that 
1367) provides that. But we consider this a feature with Tor, not a bug --- the 
1368) Internet is not flat, and it in fact does look different depending on 
1369) where you are. This feature reminds people of this fact. The easy way to 
1370) avoid this "feature" is to use 
1371) <a href="https://google.com/ncr">https://google.com/ncr</a>.

1372) </p>
1373) <p>

1374) Note that Google search URLs take name/value pairs as arguments and one 
1375) of those names is "hl". If you set "hl" to "en" then Google will return 
1376) search results in English regardless of what Google server you have been 
1377) sent to. On a query this looks like: 
1378) </p>
1379) <pre>https://encrypted.google.com/search?q=online%20anonymity&hl=en

1380) </pre>

1381) <p>

1382) Another method is to simply use your country code for accessing Google. 
1383) This can be google.be, google.de, google.us and so on. 

1384) </p>
1385) <hr />

1386) <a id="GmailWarning"></a>

1387) <h3><a class="anchor" href="#GmailWarning">Gmail warns me that my

1388) account may have been compromised.</a></h3>

1389) 
1390) <p>
1391) Sometimes, after you've used Gmail over Tor, Google presents a
1392) pop-up notification that your account may have been compromised.
1393) The notification window lists a series of IP addresses and locations
1394) throughout the world recently used to access your account.
1395) </p>
1396) 
1397) <p>
1398) In general this is a false alarm: Google saw a bunch of logins from

1399) different places, as a result of running the service via Tor, and
1400) decided

1401) it was a good idea to confirm the account was being accessed by it's
1402) rightful owner.
1403) </p>
1404) 
1405) <p>
1406) Even though this may be a biproduct of using the service via tor,
1407) that doesn't mean you can entirely ignore the warning. It is
1408) <i>probably</i> a false positive, but it might not be since it is
1409) possible for someone to hijack your Google cookie.
1410) </p>
1411) 
1412) <p>
1413) Cookie hijacking is possible by either physical access to your computer
1414) or by watching your network traffic.  In theory only physical access
1415) should compromise your system because Gmail and similar services
1416) should only send the cookie over an SSL link. In practice, alas, it's <a

1417) href="http://fscked.org/blog/fully-automated-active-https-cookie-
1418) hijacking">

1419) way more complex than that</a>.
1420) </p>
1421) 
1422) <p>
1423) And if somebody <i>did</i> steal your google cookie, they might end
1424) up logging in from unusual places (though of course they also might
1425) not). So the summary is that since you're using Tor, this security
1426) measure that Google uses isn't so useful for you, because it's full of
1427) false positives. You'll have to use other approaches, like seeing if
1428) anything looks weird on the account, or looking at the timestamps for
1429) recent logins and wondering if you actually logged in at those times.
1430) </p>
1431) 
1432) <hr>
1433) 

1434) <a id="NeedToUseAProxy"></a>

1435) <h3><a class="anchor" href="#NeedToUseAProxy">My internet connection 
1436) requires an HTTP or SOCKS Proxy</a></h3>

1437) 
1438) <p>
1439) You can set Proxy IP address, port, and authentication information in 
1440) Tor Browser's Network Settings. If you're using Tor another way, check 
1441) out the HTTPProxy and HTTPSProxy config options in the <a 
1442) href="https://www.torproject.org/docs/tor-manual.html.en">man page</a>, 
1443) and modify your torrc file accordingly. You will need an HTTP proxy for 
1444) doing GET requests to fetch the Tor directory, and you will need an 
1445) HTTPS proxy for doing CONNECT requests to get to Tor relays. (It's fine 
1446) if they're the same proxy.) Tor also recognizes the torrc options 
1447) Socks4Proxy and Socks5Proxy. 
1448) </p>
1449) <p>

1450) Also read up on the HTTPProxyAuthenticator and HTTPSProxyAuthenticator 
1451) options if your proxy requires auth. We only support basic auth currently, 
1452) but if you need NTLM authentication, you may find <a 

1453) href="http://archives.seul.org/or/talk/Jun-2005/msg00223.html">this post 
1454) in the archives</a> useful. 
1455) </p>
1456) <p>
1457) If your proxies only allow you to connect to certain ports, look at the 
1458) entry on <a href="#FirewallPorts">Firewalled clients</a> for how 
1459) to restrict what ports your Tor will try to access. 
1460) </p>
1461) 
1462) <hr>
1463) 

1464) <a id="CantSetProxy"></a>
1465) <h3><a class="anchor" href="#CantSetProxy">What should I do if I can't 
1466) set a proxy with my application?</a></h3>
1467) 
1468) <p>
1469) On Unix, we recommend you give <a 
1470) href="https://github.com/dgoulet/torsocks/">torsocks</a> a try. 
1471) Alternative proxifying tools like <a 
1472) href="http://www.dest-unreach.org/socat/">socat</a> and <a 
1473) href="http://proxychains.sourceforge.net/">proxychains</a> are also 
1474) available.</p>
1475) <p> 
1476) The Windows way to force applications through Tor is less clear. <a 
1477) href="http://freecap.ru/eng/">Some</a> <a 
1478) href="http://www.freehaven.net/~aphex/torcap/">tools</a> have been <a 
1479) href="http://www.crowdstrike.com/community-tools/index.html#tool-79">proposed
1480) </a>, but we'd also like to see further testing done here. 
1481) </p>
1482) 
1483) <hr>
1484) 

1485)     <a id="WhereDidVidaliaGo"></a>
1486)     <h3><a class="anchor" href="#WhereDidVidaliaGo">Where did the world map 
1487)     (Vidalia) go?</a></h3>
1488) 
1489)     <p>Vidalia has been replaced with Tor Launcher, which is a Firefox 
1490)     extension that provides similar functionality. Unfortunately, circuit 
1491)     status reporting is still missing, but we are <a 
1492)     href="https://trac.torproject.org/projects/tor/ticket/8641">working 
1493)     on providing it</a>. </p>
1494) 
1495)     <p>In the meantime, we are providing standalone Vidalia packages for 
1496)     people who still want the map. Windows and Linux versions are <a 

1497)     href="https://people.torproject.org/~erinn/vidalia-standalone-bundles/">

1498)     available here</a>.</p> 

1499) 
1500)     <p>To use these packages, extract them, then run the startup script. 
1501)     On Windows, this is "Start Vidalia.exe". On Linux, it is start-vidalia. 
1502)     They can be placed in a different directory from TBB (and likely should 
1503)     be). </p>
1504) 
1505)     <p>This Vidalia package will only run properly if Tor Browser has already 
1506)     been launched. You cannot start it before launching Tor Browser. </p>
1507) 
1508)     <p>MacOS is still under development, but in the mean time you can modify 
1509)     your TBB 2.x to be a standalone Vidalia (and then use it after starting 
1510)     TBB 3.x) by opening your TBB 2.x vidalia.conf file in an editor and 
1511)     replacing its contents with just these lines:</p>
1512) 
1513)     <pre>
1514)     [General]
1515)     LanguageCode=en
1516) 
1517)     [Tor]
1518)     ControlPort=9151
1519)     TorExecutable=.
1520)     Torrc=.
1521)     DataDirectory=.
1522)     AuthenticationMethod=cookie
1523)     </pre> 
1524) 
1525)     <hr>
1526) 
1527)     <a id="DisableJS"></a>
1528)     <h3><a class="anchor" href="#DisableJS">How do I disable JavaScript?</a>
1529)     </h3>
1530) 
1531)     <p>Alas, Mozilla decided to get rid of the config checkbox for JavaScript 
1532)     from earlier Firefox versions. And since TBB 3.5 is based on Firefox 24 
1533)     (FF17 is unmaintained), that means TBB 3.5 doesn't have the config 
1534)     checkbox anymore either, which is unfortunate.</p>
1535) 
1536)     <p>The simplest way to disable JavaScript in TBB 3.5 is to click on the 
1537)     Noscript "S" (between the green onion and the address bar), and select 
1538)     "Forbid scripts globally". Note that vanilla NoScript actually whitelists 
1539)     several domains even when you try to disable scripts globally, whereas 
1540)     Tor Browser's NoScript configuration disables all of them. </p>
1541) 
1542)     <p>The more klunky way to disable JavaScript is to go to about:config, 
1543)     find javascript.enabled, and set it to false.</p>
1544) 
1545)     <p>There is also a very simple addon available at addons.mozilla.org
1546)     called QuickJS, which provides a toolbar toggle for the javascript.enabled
1547)     about:config control. There are no configuration options for the addon, 
1548)     it just switches the javascript.enabled entry between true and false and 
1549)     provides a button for it. </p>
1550) 
1551)     <p>If you want to be extra safe, use both the about:config setting and 
1552)     NoScript. </p>
1553) 
1554)     <p>As for whether you should disable it or leave it enabled, that's <a 

1555)     href="#TBBJavaScriptEnabled">a tradeoff we leave to you</a>.</p>

1556) 
1557)     <hr>
1558) 
1559)     <a id="VerifyDownload"></a>
1560)     <h3><a class="anchor" href="#VerifyDownload">How do I verify the download
1561)     (sha256sums.txt)?</a></h3>
1562) 
1563)     <p>You can still verify your Tor Browser download by downloading the 
1564)     signature file (.asc) along with your package and <a 
1565)     href="https://www.torproject.org/docs/verifying-signatures.html.en">
1566)     checking the GPG signature</a> as before. We now have an additional 
1567)     verification method that allows you to verify the build as well as 
1568)     the download.</p>
1569) 
1570)     <ul>
1571)       <li>Download the Tor Browser package, the sha256sums.txt file, and the
1572)       sha256sums signature files. They can all be found in the same directory 
1573)       under <a href="https://www.torproject.org/dist/torbrowser/">
1574)       https://www.torproject.org/dist/torbrowser/</a>, for example in 3.5 
1575)       for TBB 3.5.</li>
1576)       <li>Retrieve the signers' GPG keys. This can be done from the command 
1577)       line by entering something like 
1578)       <pre>gpg --keyserver keys.mozilla.org --recv-keys 0x29846B3C683686CC</pre>
1579)       (This will bring you developer Mike Perry's public key. Other 
1580)       developers' key IDs can be found on
1581)       <a href="https://www.torproject.org/docs/signing-keys.html.en">this 
1582)       page</a>.)</li>
1583)       <li>Verify the sha256sums.txt file by executing this command:
1584)       <pre>gpg --verify &lt;NAME OF THE SIGNATURE FILE&gt;.asc sha256sums.txt</pre></li>
1585)       <li>You should see a message like "Good signature from &lt;DEVELOPER 
1586)       NAME&gt;". If you don't, there is a problem. Try these steps again.</li>
1587)       <li>Now you can take the sha256sum of the Tor Browser package. On 
1588)       Windows you can use the <a href="http://md5deep.sourceforge.net/">
1589)       hashdeep utility</a> and run
1590)       <pre>C:\location\where\you\saved\hashdeep -c sha256sum &lt;TOR BROWSER FILE NAME&gt;.exe</pre>
1591)       On Mac or Linux you can run <pre>sha256sum &lt;TOR BROWSER FILE NAME&gt;.zip</pre> or <pre>sha256sum &lt;TOR BROWSER FILE NAME&gt;.tar.gz</pre> without having to download a utility.</li>
1592)       <li>You will see a string of letters and numbers.</li>
1593)       <li>Open sha256sums.txt in a text editor.</li>
1594)       <li>Locate the name of the Tor Browser file you downloaded.</li>
1595)       <li>Compare the string of letters and numbers to the left of your
1596)       filename with the string of letters and numbers that appeared 
1597)       on your command line. If they match, you've successfully verified the 
1598)       build.</li> 
1599)     </ul>
1600) 
1601)     <p><a href="https://github.com/isislovecruft/scripts/blob/master/verify-gitian-builder-signatures">
1602)     Scripts</a> to <a 
1603)     href="http://tor.stackexchange.com/questions/648/how-to-verify-tor-browser-bundle-tbb-3-x">automate
1604)     </a> these steps have been written, but to use them you will need to 
1605)     modify them yourself with the latest Tor Browser Bundle filename.</p>
1606) 
1607)     <hr>
1608) 
1609)     <a id="PluggableTransports"></a>
1610)     <h3><a class="anchor" href="#PluggableTransports">How do I use pluggable transports?</a></h3>
1611) 
1612)     <p>
1613)     For now, the Pluggable Transports-capable TBB is still a separate 
1614)     unofficial package. Download them <a 
1615)     href="https://people.torproject.org/~dcf/pt-bundle/3.5-pt20131217/">
1616)     here</a>. We hope to have combined packages available in a beta soon.
1617)     </p>
1618) 
1619)     <p>
1620)     The separate Pluggable Transports-capable TBB is different from the 
1621)     Pluggable Transports bundles that have been released in the past. 
1622)     They include the programs necessary to use obfsproxy and flash proxy, 
1623)     but the pluggable transports are not enabled by default. You must 
1624)     enable them manually by adding Bridge lines to the torrc file. 
1625)     (Please see ticket <a 
1626)     href="https://trac.torproject.org/projects/tor/ticket/10418">#10418</a> 
1627)     for how we hope to make it easier to do in the future.)
1628)     </p>
1629) 
1630)     <p>
1631)     To enable <b>obfsproxy</b>, edit the file called Data/Tor/torrc inside the 
1632)     bundle and add the lines: 
1633)     </p>
1634) 
1635)     <pre>
1636) Bridge obfs3 83.212.101.2:42782 2ADFE7AA8D272C520D1FBFBF4E413F3A1B26313D
1637) Bridge obfs3 83.212.101.2:443 2ADFE7AA8D272C520D1FBFBF4E413F3A1B26313D
1638) Bridge obfs3 169.229.59.74:31493 AF9F66B7B04F8FF6F32D455F05135250A16543C9
1639) Bridge obfs3 169.229.59.75:46328 AF9F66B7B04F8FF6F32D455F05135250A16543C9
1640) Bridge obfs3 209.141.36.236:45496
1641) Bridge obfs3 208.79.90.242:35658
1642) Bridge obfs3 109.105.109.163:38980 9D7259A696F7DAB073043B28114112A46D36CFFD
1643) Bridge obfs3 109.105.109.163:47779 844B1F53FFD548C998F8D3B01B7E19FA07C3396E
1644) Bridge obfs2 83.212.100.216:47870 1F01A7BB60F49FC96E0850A6BAD6D076DFEFAF80
1645) Bridge obfs2 83.212.96.182:46602 6F058CBEF888EB20D1DEB9886909F1E812245D41
1646) Bridge obfs2 70.182.182.109:54542 94C9E691688FAFDEC701A0788BD15BE8AD34ED35
1647) Bridge obfs2 128.31.0.34:1051 CA7434F14A898C7D3427B8295A7F83446BC7F496
1648) Bridge obfs2 83.212.101.2:45235 2ADFE7AA8D272C520D1FBFBF4E413F3A1B26313D
1649)     </pre>
1650)     <p>
1651)     To enable <b>flash proxy</b>, edit the file called Data/Tor/torrc inside the 
1652)     bundle and add the lines: 
1653)     </p>
1654)     <pre>
1655) LearnCircuitBuildTimeout 0
1656) CircuitBuildTimeout 60
1657) Bridge flashproxy 0.0.1.0:1
1658)     </pre>
1659) 
1660)     <hr>
1661) 
1662)     <a id="NewIdentityClosingTabs"></a>
1663)     <h3><a class="anchor" href="#NewIdentityClosingTabs">Why does "New 
1664)     Identity" close all my open tabs?</a></h3>
1665) 
1666)     <p>
1667)     That's actually a feature, since it's discarding your application-level 
1668)     browser data too. But it sure is a surprising feature, for people who 
1669)     are used to Vidalia's "new identity" behavior.
1670)     </p>
1671) 
1672)     <p>
1673)     We're working on ways to make the behavior less surprising, e.g. a popup 
1674)     warning or auto restoring tabs. See ticket <a 
1675)     href="https://trac.torproject.org/projects/tor/ticket/9906">#9906</a> and 
1676)     ticket <a href="https://trac.torproject.org/projects/tor/ticket/10400">
1677)     #10400</a> to follow progress there.
1678)     </p>
1679) 
1680)     <p>
1681)     In the mean time, you can get Vidalia's old "newnym" functionality by 
1682)     attaching a Vidalia to your TBB3.x. See the instructions above.
1683)     </p>
1684) 
1685)     <hr>
1686) 
1687)     <a id="ConfigureRelayOrBridge"></a>
1688)     <h3><a class="anchor" href="#ConfigureRelayOrBridge">How do I configure Tor as a relay or bridge?</a></h3>
1689) 
1690)     <p>
1691)     You've got three options. 
1692)     </p>
1693) 
1694)     <p>
1695)     First (best option), if you're on Linux, you can install the system 
1696)     Tor package (e.g. apt-get install tor) and then set it up to be a relay 
1697)     (<a href="https://www.torproject.org/docs/tor-relay-debian">instructions</a>). 
1698)     You can then use TBB independent of that.
1699)     </p>
1700) 
1701)     <p>
1702)     Second (simpler option), if you're on Windows, you can fetch the separate 
1703)     "Vidalia relay bundle" or "Vidalia bridge bundle" from the download page 
1704)     and then use that (again you can use TBB independent of it). 
1705)     </p>
1706) 
1707)     <p>
1708)     Third (complex option), you can either hook your Vidalia up to TBB (as 
1709)     described in the FAQ above) or edit your torrc file (in Data/Tor/torrc) 
1710)     directly to add the following lines: 
1711)     </p>
1712)     <pre>
1713)     ORPort 443
1714)     Exitpolicy reject *:*
1715)     BridgeRelay 1  # only add this line if you want to be a bridge
1716)     </pre>
1717)     <p>
1718)     If you've installed <a 
1719)     href="https://www.torproject.org/projects/obfsproxy-debian-instructions.html.en#instructions">Obfsproxy</a>, 
1720)     you'll need to add one more line:
1721)     </p>
1722)     <pre>
1723)     ServerTransportPlugin obfs3 exec /usr/bin/obfsproxy managed
1724)     </pre>
1725)     <p>
1726)     This third option is pretty klunky right now; see e.g. <a 
1727)     href="https://trac.torproject.org/projects/tor/ticket/10449">this bug</a>; 
1728)     but we're hoping it will become an easy option in the future. 
1729)     </p>
1730) 
1731)     <hr>
1732) 
1733)     <a id="Timestamps"></a>
1734)     <h3><a class="anchor" href="#Timestamps">Why are the file timestamps 
1735)     from 2000?</a></h3>
1736) 
1737)     <p>One of the huge new features in TBB 3.x is the "deterministic build" 
1738)     process, which allows many people to build the Tor Browser Bundle and 
1739)     verify that they all make exactly the same package. See Mike's <a 
1740)     href="https://blog.torproject.org/blog/deterministic-builds-part-one-cyberwar-and-global-compromise">first 
1741)     blog</a> post for the motivation, and his <a 
1742)     href="https://blog.torproject.org/blog/deterministic-builds-part-two-technical-details">second
1743)     blog post</a> for the technical details of how we do it. 
1744)     </p>
1745) 
1746)     <p>Part of creating identical builds is having everybody use the same 
1747)     timestamp. Mike picked the beginning of 2000 for that time. The reason 
1748)     you might see 7pm in 1999 is because of time zones. </p>
1749) 
1750)     <hr>
1751) 
1752)     <a id="SourceCode"></a>
1753)     <h3><a class="anchor" href="#SourceCode">Where is the source code for the bundle? How do I verify a build?</a></h3>
1754) 
1755)     <p>
1756)     Start with <a href="https://gitweb.torproject.org/builders/tor-browser-bundle.git">https://gitweb.torproject.org/builders/tor-browser-bundle.git</a> and <a href="https://gitweb.torproject.org/builders/tor-browser-bundle.git/blob/HEAD:/gitian/README.build">https://gitweb.torproject.org/builders/tor-browser-bundle.git/blob/HEAD:/gitian/README.build</a>.
1757)     </p>
1758) 
1759) 

1760) <hr>
1761) 

1762) <a id="torrc"></a>

1763) <h3><a class="anchor" href="#torrc">I'm supposed to "edit my torrc".
1764) What does that mean?</a></h3>

1765) 
1766) <p>
1767) Tor installs a text file called torrc that contains configuration
1768) instructions for how your Tor program should behave. The default

1769) configuration should work fine for most Tor users. 

1770) </p>

1771) <p>

1772) If you installed Tor Browser Bundle, look for

1773) <code>Data/Tor/torrc</code> inside your Tor Browser Bundle directory. 
1774) </p>
1775) <p>
1776) Core tor puts the torrc file in <code>/usr/local/etc/tor/torrc</code> if you compiled tor from source, and <code>/etc/tor/torrc</code> or <code>/etc/torrc</code> if you installed a pre-built package.</p>

1777) 
1778) <p>

1779) Once you've changed your torrc, you will need to restart tor for the
1780) changes to take effect. (For advanced users, note that

1781) you actually only need to send Tor a HUP signal, not actually restart
1782) it.)

1783) </p>
1784) 
1785) <p>

1786) For other configuration options you can use, see the <a href="<page
1787) docs/tor-manual>">Tor manual page</a>. Have a look at <a 

1788) href="https://gitweb.torproject.org/tor.git/blob/HEAD:/src/config/torrc.sample.in">
1789) the sample torrc file</a> for hints on common configurations. Remember, all 
1790) lines beginning with # in torrc are treated as comments and have no effect 
1791) on Tor's configuration.

1792) </p>
1793) 
1794) <hr>
1795) 

1796) <a id="Logs"></a>

1797) <h3><a class="anchor" href="#Logs">How do I set up logging, or see Tor's
1798) logs?</a></h3>

1799) 
1800) <p>

1801) If you installed a Tor bundle that includes Vidalia, then Vidalia has a

1802) window called "Message Log" that will show you Tor's log messages. Click
1803) on "Advanced" to see more details. You can click on "Settings" to change
1804) your log verbosity or save the messages to a file. You're all set.

1805) </p>
1806) 
1807) <p>
1808) If you're not using Vidalia, you'll have to go find the log files by

1809) hand. Here are some likely places for your logs to be:

1810) </p>
1811) 
1812) <ul>
1813) <li>On OS X, Debian, Red Hat, etc, the logs are in /var/log/tor/
1814) </li>

1815) <li>On Windows, there are no default log files currently. If you enable
1816) logs in your torrc file, they default to <code>\username\Application
1817) Data\tor\log\</code> or <code>\Application Data\tor\log\</code>
1818) </li>
1819) <li>If you compiled Tor from source, by default your Tor logs to <a
1820) href="http://en.wikipedia.org/wiki/Standard_streams">"stdout"</a>
1821) at log-level notice. If you enable logs in your torrc file, they
1822) default to <code>/usr/local/var/log/tor/</code>.

1823) </li>
1824) </ul>
1825) 
1826) <p>

1827) To change your logging setup by hand, <a href="#torrc">edit your
1828) torrc</a>

1829) and find the section (near the top of the file) which contains the
1830) following line:

1831) </p>
1832) 
1833) <pre>

1834) \## Logs go to stdout at level "notice" unless redirected by something
1835) \## else, like one of the below lines.

1836) </pre>

1837) 
1838) <p>

1839) For example, if you want Tor to send complete debug, info, notice, warn,

1840) and err level messages to a file, append the following line to the end
1841) of the section:
1842) </p>
1843) 
1844) <pre>
1845) Log debug file c:/program files/tor/debug.log
1846) </pre>
1847) 
1848) <p>

1849) Replace <code>c:/program files/tor/debug.log</code> with a directory
1850) and filename for your Tor log.

1851) </p>
1852) 
1853) <hr>
1854) 

1855) 
1856) <a id="LogLevel"></a>
1857) <h3><a class="anchor" href="#LogLevel">What log level should I use?</a></h3>
1858) 
1859) <p>

1860) There are five log levels (also called "log severities") you might see in 
1861) Tor's logs:

1862) </p>
1863) 
1864) <ul>

1865)     <li>"err": something bad just happened, and we can't recover. Tor will 
1866)     exit.</li>
1867)     <li>"warn": something bad happened, but we're still running. The bad 
1868)     thing might be a bug in the code, some other Tor process doing something 
1869)     unexpected, etc. The operator should examine the message and try to 
1870)     correct the problem.</li>

1871)     <li>"notice": something the operator will want to know about.</li>

1872)     <li>"info": something happened (maybe bad, maybe ok), but there's 
1873)     nothing you need to (or can) do about it.</li>

1874)     <li>"debug": for everything louder than info. It is quite loud indeed.</li> 
1875) </ul>
1876) 
1877) <p>

1878) Alas, some of the warn messages are hard for ordinary users to correct -- the 
1879) developers are slowly making progress at making Tor automatically react 
1880) correctly for each situation.

1881) </p>
1882) 
1883) <p>

1884) We recommend running at the default, which is "notice". You will hear about 
1885) important things, and you won't hear about unimportant things.

1886) </p>
1887) 
1888) <p>

1889) Tor relays in particular should avoid logging at info or debug in normal 
1890) operation, since they might end up recording sensitive information in 
1891) their logs. 

1892) </p>
1893) 

1894) <hr>
1895) 

1896) <a id="DoesntWork"></a>

1897) <h3><a class="anchor" href="#DoesntWork">I installed Tor but it's not
1898) working.</a></h3>

1899) 
1900) <p>

1901) Once you've got the Tor bundle up and running, the first question to
1902) ask is whether your Tor client is able to establish a circuit.

1903) </p>
1904) 
1905) <p>If Tor can establish a circuit, the onion icon in

1906) Vidalia will turn green (and if you're running Tor Browser Bundle, it
1907) will
1908) automatically launch a browser for you). You can also check in the
1909) Vidalia

1910) Control Panel to make sure it says "Connected to the Tor
1911) network!" under Status. For those not using Vidalia, check your <a

1912) href="#Logs">Tor logs</a> for

1913) a line saying that Tor "has successfully opened a circuit. Looks like
1914) client functionality is working."
1915) </p>
1916) 
1917) <p>
1918) If Tor can't establish a circuit, here are some hints:
1919) </p>
1920) 
1921) <ol>
1922) <li>Are you sure Tor is running? If you're using Vidalia, you may have
1923) to click on the onion and select "Start" to launch Tor.</li>
1924) <li>Check your system clock. If it's more than a few hours off, Tor will

1925) refuse to build circuits. For Microsoft Windows users, synchronize your
1926) clock under the clock -> Internet time tab. In addition, correct the

1927) day and date under the 'Date & Time' Tab. Also make sure your time
1928) zone is correct.</li>

1929) <li>Is your Internet connection <a href="#FirewallPorts">firewalled
1930) by port</a>, or do you normally need to use a <a

1931) href="<#NeedToUseAProxy">proxy</a>?

1932) </li>

1933) <li>Are you running programs like Norton Internet Security or SELinux
1934) that

1935) block certain connections, even though you don't realize they do? They
1936) could be preventing Tor from making network connections.</li>
1937) <li>Are you in China, or behind a restrictive corporate network firewall
1938) that blocks the public Tor relays? If so, you should learn about <a

1939) href="<page docs/bridges>">Tor bridges</a>.</li>

1940) <li>Check your <a href="#Logs">Tor logs</a>. Do they give you any hints
1941) about what's going wrong?</li>

1942) </ol>
1943) 
1944) <hr />
1945) 

1946) <a id="TorCrash"></a>
1947) <h3><a class="anchor" href="#TorCrash">My Tor keeps crashing.</a></h3>
1948) <p>
1949)  We want to hear from you! There are supposed to be zero crash bugs in Tor. 
1950)  This FAQ entry describes the best way for you to be helpful to us. But even 
1951)  if you can't work out all the details, we still want to hear about it, so 
1952)  we can help you track it down. 
1953) </p>
1954) <p>
1955) First, make sure you're using the latest version of Tor (either the latest 
1956) stable or the latest development version). 
1957) </p>
1958) <p>
1959) Second, make sure your version of libevent is new enough. We recommend at 
1960) least libevent 1.3a. 
1961) </p>
1962) <p>
1963) Third, see if there's already an entry for your bug in the <a 
1964) href="https://bugs.torproject.org/">Tor bugtracker</a>. If so, 
1965) check if there are any new details that you can add. 
1966) </p>
1967) <p>
1968) Fourth, is the crash repeatable? Can you cause the crash? Can 
1969) you isolate some of the circumstances or config options that 
1970) make it happen? How quickly or often does the bug show up? 
1971) Can you check if it happens with other versions of Tor, for 
1972) example the latest stable release? 
1973) </p>
1974) <p>
1975) Fifth, what sort of crash do you get? 
1976) </p>
1977) <ul>
1978) <li>
1979) Does your Tor log include an "assert failure"? If so, please 
1980) tell us that line, since it helps us figure out what's going on. 
1981) Tell us the previous couple of log messages as well, especially 
1982) if they seem important. 
1983) </li>
1984) <li>
1985) If it says "Segmentation fault - core dumped" then you need to 
1986) do a bit more to track it down. Look for a file like "core" or 
1987) "tor.core" or "core.12345" in your current directory, or in your 
1988) Data Directory. If it's there, run "gdb tor core" and then "bt", 
1989) and include the output. If you can't find a core, run "ulimit -c 
1990) unlimited", restart Tor, and try to make it crash again. (This core 
1991) thing will only work on Unix -- alas, tracking down bugs on Windows 
1992) is harder. If you're on Windows, can you get somebody to duplicate 
1993) your bug on Unix?)
1994) </li>
1995) <li>
1996) If Tor simply vanishes mysteriously, it probably is a segmentation 
1997) fault but you're running Tor in the background (as a daemon) so you 
1998) won't notice. Go look at the end of your log file, and look for a 
1999) core file as above. If you don't find any good hints, you should 
2000) consider running Tor in the foreground (from a shell) so you can 
2001) see how it dies. Warning: if you switch to running Tor in the foreground, 
2002) you might start using a different torrc file, with a different default 
2003) Data Directory; see the <a href="#UpgradeOrMove">relay-upgrade FAQ entry</a> 
2004) for details. 
2005) </li>
2006) <li>
2007) If it's still vanishing mysteriously, perhaps something else is killing it? 
2008) Do you have resource limits (ulimits) configured that kill off processes 
2009) sometimes? (This is especially common on OpenBSD.) On Linux, try running 
2010) "dmesg" to see if the out-of-memory killer removed your process. (Tor will 
2011) exit cleanly if it notices that it's run out of memory, but in some cases 
2012) it might not have time to notice.) In very rare circumstances, hardware 
2013) problems could also be the culprit. 
2014) </li>
2015) </ul>
2016) <p>
2017) Sixth, if the above ideas don't point out the bug, consider increasing your 
2018) log level to "loglevel debug". You can look at the log-configuration FAQ 
2019) entry for instructions on what to put in your torrc file. If it usually 
2020) takes a long time for the crash to show up, you will want to reserve a whole 
2021) lot of disk space for the debug log. Alternatively, you could just send 
2022) debug-level logs to the screen (it's called "stdout" in the torrc), and then 
2023) when it crashes you'll see the last couple of log lines it had printed. 
2024) (Note that running with verbose logging like this will slow Tor down 
2025) considerably, and note also that it's generally not a good idea security-wise 
2026) to keep logs like this sitting around.) 
2027) </p>
2028) 
2029) <hr />
2030) 

2031) <a id="VidaliaPassword"></a>

2032) <h3><a class="anchor" href="#VidaliaPassword">Tor/Vidalia prompts for a
2033) password at start.</a></h3>

2034) 
2035) <p>
2036) Vidalia interacts with the Tor software via Tor's "control port". The
2037) control port lets Vidalia receive status updates from Tor, request a new
2038) identity, configure Tor's settings, etc. Each time Vidalia starts Tor,
2039) Vidalia sets a random password for Tor's control port to prevent other
2040) applications from also connecting to the control port and potentially
2041) compromising your anonymity.
2042) </p>
2043) 
2044) <p>
2045) Usually this process of generating and setting a random control password
2046) happens in the background. There are three common situations, though,
2047) where Vidalia may prompt you for a password:
2048) </p>
2049) 
2050) <ol>
2051) <li>You're already running Vidalia and Tor. For example, this situation
2052) can happen if you installed the Vidalia bundle and now you're trying to
2053) run the Tor Browser Bundle. In that case, you'll need to close the old
2054) Vidalia and Tor before you can run this one.
2055) </li>
2056) <li>Vidalia crashed, but left Tor running with the last known random
2057) password. After you restart Vidalia, it generates a new random password,

2058) but Vidalia can't talk to Tor, because the random passwords are
2059) different.

2060) <br />

2061) If the dialog that prompts you for a control password has a Reset
2062) button,

2063) you can click the button and Vidalia will restart Tor with a new random
2064) control password.
2065) <br />
2066) If you do not see a Reset button, or if Vidalia is unable to restart
2067) Tor for you, you can still fix the problem manually. Simply go into your
2068) process or task manager, and terminate the Tor process. Then use Vidalia
2069) to restart Tor and all will work again.
2070) </li>
2071) <li>You had previously set Tor to run as a Windows NT service. When Tor
2072) is set to
2073) run as a service, it starts up when the system boots. If you configured
2074) Tor to start as a service through Vidalia, a random password was set
2075) and saved in Tor. When you reboot, Tor starts up and uses the random
2076) password it saved. You login and start up Vidalia. Vidalia attempts to
2077) talk to the already running Tor. Vidalia generates a random password,
2078) but it is different than the saved password in the Tor service.
2079) <br />
2080) You need to reconfigure Tor to not be a service. See the FAQ entry on

2081) <a href="#NTservice">running Tor as a

2082) Windows NT service</a>

2083) for more information on how to remove the Tor service.
2084) </li>
2085) </ol>
2086) 

2087)     <hr>

2088) 

2089)     <a id="ChooseEntryExit"></a>

2090)     <h3><a class="anchor" href="#ChooseEntryExit">Can I control which
2091) nodes (or country) are used for entry/exit?</a></h3>

2092) 

2093)     <p>

2094)     Yes. You can set preferred entry and exit nodes as well as
2095)     inform Tor which nodes you do not want to use.

2096)     The following options can be added to your config file <a
2097)     href="#torrc">"torrc"</a> or specified on the command line:

2098)     </p>
2099)     <dl>
2100)       <dt><tt>EntryNodes $fingerprint,$fingerprint,...</tt></dt>

2101)         <dd>A list of preferred nodes to use for the first hop in the
2102) circuit, if possible.

2103)         </dd>
2104)       <dt><tt>ExitNodes $fingerprint,$fingerprint,...</tt></dt>

2105)         <dd>A list of preferred nodes to use for the last hop in the
2106) circuit, if possible.

2107)         </dd>
2108)       <dt><tt>ExcludeNodes $fingerprint,$fingerprint,...</tt></dt>

2109)         <dd>A list of nodes to never use when building a circuit.

2110)         </dd>
2111)       <dt><tt>ExcludeExitNodes $fingerprint,$fingerprint,...</tt></dt>

2112)         <dd>A list of nodes to never use when picking an exit.

2113)             Nodes listed in <tt>ExcludeNodes</tt> are automatically in
2114) this list.

2115)         </dd>
2116)     </dl>
2117)     <p>

2118)     <em>We recommend you do not use these</em>

2119)     — they are intended for testing and may disappear in future
2120) versions.

2121)     You get the best security that Tor can provide when you leave the
2122)     route selection to Tor; overriding the entry / exit nodes can mess
2123)     up your anonymity in ways we don't understand.

2124)     </p>
2125)     <p>

2126)     Note also that not every circuit is used to deliver traffic outside of 
2127)     the Tor network. It is normal to see non-exit circuits (such as those 
2128)     used to connect to hidden services, those that do directory fetches, 
2129)     those used for relay reachability self-tests, and so on) that end at 
2130)     a non-exit node. To keep a node from being used entirely, see 
2131)     <tt>ExcludeNodes</tt> and <tt>StrictNodes</tt> in the 
2132)     <a href="<page docs/tor-manual>">manual</a>.

2133)     </p>
2134)     <p>

2135)     Instead of <tt>$fingerprint</tt> you can also specify a <a

2136) 
2137) href="https://secure.wikimedia.org/wikipedia/en/wiki/ISO_3166-1_alpha-2"
2138) >2

2139)     letter ISO3166 country code</a> in curly braces (for example <tt>{de}</tt>),

2140)     or an ip address pattern (for example 255.254.0.0/8), or a node
2141)     nickname. Make sure there are no spaces between the commas and the
2142)     list items.

2143)     </p>
2144)     <p>

2145)     If you want to access a service directly through Tor's Socks
2146) interface

2147)     (eg. using ssh via connect.c), another option is to set up an

2148)     internal mapping in your configuration file using
2149) <tt>MapAddress</tt>.

2150)     See the manual page for details.
2151)     </p>

2152) 

2153)     <hr>

2154) 

2155) <a id="FirewallPorts"></a>

2156) <h3><a class="anchor" href="#FirewallPorts">My firewall only allows a
2157) few outgoing ports.</a></h3>

2158) 
2159) <p>
2160) If your firewall works by blocking ports, then you can tell Tor to only

2161) use the ports that your firewall permits by adding "FascistFirewall 1"
2162) to

2163) your <a href="<page docs/faq>#torrc">torrc

2164) configuration file</a>, or by clicking "My firewall only lets me connect
2165) to certain ports" in Vidalia's Network Settings window.
2166) </p>
2167) 
2168) <p>
2169) By default, when you set this Tor assumes that your firewall allows only
2170) port 80 and port 443 (HTTP and HTTPS respectively). You can select a
2171) different set of ports with the FirewallPorts torrc option.
2172) </p>
2173) 
2174) <p>
2175) If you want to be more fine-grained with your controls, you can also
2176) use the ReachableAddresses config options, e.g.:
2177) </p>
2178) 
2179) <pre>
2180)   ReachableDirAddresses *:80
2181)   ReachableORAddresses *:443
2182) </pre>
2183) 
2184) <hr>

2185) 

2186)     <a id="DefaultExitPorts"></a>
2187)     <h3><a class="anchor" href="#DefaultExitPorts">Is there a list of default exit 

2188)     ports?</a></h3>

2189)     <p>

2190) The default open ports are listed below but keep in mind that, any port or 
2191) ports can be opened by the relay operator by configuring it in torrc or 
2192) modifying the source code. But the default according to src/or/policies.c 
2193) from the source code release tor-0.2.4.16-rc is: 

2194)     </p>
2195)     <pre>
2196)   reject 0.0.0.0/8
2197)   reject 169.254.0.0/16
2198)   reject 127.0.0.0/8
2199)   reject 192.168.0.0/16
2200)   reject 10.0.0.0/8
2201)   reject 172.16.0.0/12
2202)   reject *:25
2203)   reject *:119
2204)   reject *:135-139
2205)   reject *:445
2206)   reject *:563
2207)   reject *:1214
2208)   reject *:4661-4666
2209)   reject *:6346-6429
2210)   reject *:6699
2211)   reject *:6881-6999
2212)   accept *:*
2213)     </pre>
2214)     <p>

2215)     A relay will block access to its own IP address, as well local network 
2216)     IP addresses. A relay always blocks itself by default. This prevents 
2217)     Tor users from accidentally accessing any of the exit operator's local 
2218)     services. 
2219)     </p>
2220) 
2221)     <hr>
2222) 

2223)     <a id="WarningsAboutSOCKSandDNSInformationLeaks"></a>
2224)     <h3><a class="anchor" href="#WarningsAboutSOCKSandDNSInformationLeaks">I 
2225)     keep seeing these warnings about SOCKS and DNS information leaks. 
2226)     Should I worry?</a></h3>
2227)     <p>
2228)     The warning is: 
2229)     </p>
2230)     <p>
2231)     Your application (using socks5 on port %d) is giving Tor only an IP 
2232)     address. Applications that do DNS resolves themselves may leak 
2233)     information. Consider using Socks4A (e.g. via Polipo or socat) instead. 
2234)     </p>
2235)     <p>
2236)     If you are running Tor to get anonymity, and you are worried about an 
2237)     attacker who is even slightly clever, then yes, you should worry. Here's why. 
2238)     </p>
2239)     <p>
2240)     <b>The Problem.</b> When your applications connect to servers on the 
2241)     Internet, they need to resolve hostnames that you can read (like 
2242)     www.torproject.org) into IP addresses that the Internet can use (like 
2243)     209.237.230.66). To do this, your application sends a request to a DNS 
2244)     server, telling it the hostname it wants to resolve. The DNS server 
2245)     replies by telling your application the IP address. 
2246)     </p>
2247)     <p>
2248)     Clearly, this is a bad idea if you plan to connect to the remote host 
2249)     anonymously: when your application sends the request to the DNS server, 
2250)     the DNS server (and anybody else who might be watching) can see what 
2251)     hostname you are asking for. Even if your application then uses Tor to 
2252)     connect to the IP anonymously, it will be pretty obvious that the user 
2253)     making the anonymous connection is probably the same person who made 
2254)     the DNS request. 
2255)     </p>
2256)     <p>
2257)     <b>Where SOCKS comes in.</b> Your application uses the SOCKS protocol 
2258)     to connect to your local Tor client. There are 3 versions of SOCKS you 
2259)     are likely to run into: SOCKS 4 (which only uses IP addresses), SOCKS 5 
2260)     (which usually uses IP addresses in practice), and SOCKS 4a (which uses 
2261)     hostnames). 
2262)     </p>
2263)     <p>
2264)     When your application uses SOCKS 4 or SOCKS 5 to give Tor an IP address, 
2265)     Tor guesses that it 'probably' got the IP address non-anonymously from a 
2266)     DNS server. That's why it gives you a warning message: you probably aren't 
2267)     as anonymous as you think. 
2268)     </p>
2269)     <p>
2270)     <b>So what can I do?</b> We describe a few solutions below. 
2271)     </p>
2272)     <ul>
2273)     <li>If your application speaks SOCKS 4a, use it. </li>
2274)     <li>If you only need one or two hosts, or you are good at programming, 
2275)     you may be able to get a socks-based port-forwarder like socat to work 
2276)     for you; see <a 
2277)     href="https://trac.torproject.org/projects/tor/wiki/doc/TorifyHOWTO">the 
2278)     Torify HOWTO</a> for examples. </li>
2279)     <li>Tor ships with a program called tor-resolve that can use the Tor 
2280)     network to look up hostnames remotely; if you resolve hostnames to IPs 
2281)     with tor-resolve, then pass the IPs to your applications, you'll be fine. 
2282)     (Tor will still give the warning, but now you know what it means.) </li>
2283) <!-- I'm not sure if this project is still maintained or not
2284) 
2285) <li>You can use TorDNS as a local DNS server to rectify the DNS leakage. See the Torify HOWTO for info on how to run particular applications anonymously. </li>
2286) !-->
2287)     </ul>
2288)     <p>If you think that you applied one of the solutions properly but still 
2289)     experience DNS leaks please verify there is no third-party application 
2290)     using DNS independently of Tor. Please see <a 
2291)     href="#AmITotallyAnonymous">the FAQ entry on whether you're really 
2292)     absolutely anonymous using Tor</a> for some examples. 
2293)     </p>
2294) 
2295)     <hr>
2296) 

2297)     <a id="SocksAndDNS"></a>
2298)     <h3><a class="anchor" href="#SocksAndDNS">How do I check if my application that uses 
2299)     SOCKS is leaking DNS requests?</a></h3>
2300) 
2301)     <p>
2302)     These are two steps you need to take here. The first is to make sure 
2303)     that it's using the correct variant of the SOCKS protocol, and the 
2304)     second is to make sure that there aren't other leaks. 
2305)     </p>
2306) 
2307)     <p>
2308)     Step one: add "TestSocks 1" to your torrc file, and then watch your 
2309)     logs as you use your application. Tor will then log, for each SOCKS 
2310)     connection, whether it was using a 'good' variant or a 'bad' one. 
2311)     (If you want to automatically disable all 'bad' variants, set 
2312)     "SafeSocks 1" in your <a href="#torrc">torrc</a> file.) 
2313)     </p>
2314) 
2315)     <p>
2316)     Step two: even if your application is using the correct variant of 
2317)     the SOCKS protocol, there is still a risk that it could be leaking 
2318)     DNS queries. This problem happens in Firefox extensions that resolve 
2319)     the destination hostname themselves, for example to show you its IP 
2320)     address, what country it's in, etc. These applications may use a safe 
2321)     SOCKS variant when actually making connections, but they still do DNS 
2322)     resolves locally. If you suspect your application might behave like 
2323)     this, you should use a network sniffer like <a 
2324)     href="https://www.wireshark.org/">Wireshark</a> and look for 
2325)     suspicious outbound DNS requests. I'm afraid the details of how to look 
2326)     for these problems are beyond the scope of a FAQ entry though -- find 
2327)     a friend to help if you have problems. 

2328)     </p>
2329) 
2330)     <hr>
2331) 

2332)     <a id="HowDoIDecide"></a>
2333)     <h3><a class="anchor" href="#HowDoIDecide">How do I decide if I should 
2334)     run a relay?</a></h3>
2335)     <p>
2336)     We're looking for people with reasonably reliable Internet connections, 
2337)     that have at least 20 kilobytes/second each way. If that's you, please 
2338)     consider <a href="https://www.torproject.org/docs/tor-relay-debian">helping 
2339)     out</a>. 
2340)     </p>
2341)     
2342)     <hr>
2343)     
2344)     <a id="WhyIsntMyRelayBeingUsedMore"></a>
2345)     <h3><a class="anchor" href="#WhyIsntMyRelayBeingUsedMore">Why isn't my 
2346)     relay being used more?</a></h3>
2347)     <p>
2348)     If your relay is relatively new then give it time. Tor decides which 
2349)     relays it uses heuristically based on reports from Bandwidth 
2350)     Authorities. These authorities take measurements of your relay's 
2351)     capacity and, over time, directs more traffic there until it reaches 
2352)     an optimal load. The lifecycle of a new relay is explained in more 
2353)     depth in <a href="https://blog.torproject.org/blog/lifecycle-of-a-new-relay">
2354)     this blog post</a>.
2355)     </p>
2356)     <p>
2357)     If you've been running a relay for a while and still having issues 
2358)     then try asking on the <a href=
2359)     "https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays/">
2360)     tor-relays list</a>. 
2361)     </p>
2362)     
2363)     <hr>
2364) 

2365)     <a id="IDontHaveAStaticIP"></a>
2366)     <h3><a class="anchor" href="#IDontHaveAStaticIP">I don't have a static 
2367)     IP.</a></h3>
2368) 
2369)     <p>
2370)     Tor can handle relays with dynamic IP addresses just fine. Just leave 
2371)     the "Address" line in your torrc blank, and Tor will guess. 
2372)     </p>
2373) 
2374)     <hr>
2375) 
2376)     <a id="ModemKeepsCrashing"></a>
2377)     <h3><a class="anchor" href="#ModemKeepsCrashing">My cable/DSL modem 
2378)     keeps crashing. What's going on?</h3></a>
2379) 
2380)     <p>
2381)     Tor relays hold many connections open at once. This is more intensive 
2382)     use than your cable modem (or other home router) would ever get normally. 
2383)     So if there are any bugs or instabilities, they might show up now. 
2384)     </p>
2385)     <p>
2386)     If your router keeps crashing, you've got two options. First, you should 
2387)     try to upgrade its firmware. If you need tips on how to do this, ask 
2388)     Google or your cable/router provider, or try the Tor IRC channel. 
2389)     </p>
2390) 
2391)     <p>
2392)     Usually the firmware upgrade will fix it. If it doesn't, you will 
2393)     probably want to get a new (better) router. 
2394)     </p>
2395) 
2396)     <hr>
2397) 
2398)     <a id="PortscannedMore"></a>
2399)     <h3><a class="anchor" href="#PortscannedMore">Why do I get portscanned 
2400)     more often when I run a Tor relay?</a></h3>
2401) 
2402)     <p>
2403)     If you allow exit connections, some services that people connect to 
2404)     from your relay will connect back to collect more information about you. 
2405)     For example, some IRC servers connect back to your identd port to record 
2406)     which user made the connection. (This doesn't really work for them, 
2407)     because Tor doesn't know this information, but they try anyway.) Also, 
2408)     users exiting from you might attract the attention of other users on the 
2409)     IRC server, website, etc. who want to know more about the host they're 
2410)     relaying through. 
2411)     </p>
2412)     <p>
2413)     Another reason is that groups who scan for open proxies on the Internet 
2414)     have learned that sometimes Tor relays expose their socks port to the 
2415)     world. We recommend that you bind your socksport to local networks only. 
2416)     </p>
2417)     <p>
2418)     In any case, you need to keep up to date with your security. See this <a 
2419)     href="https://trac.torproject.org/projects/tor/wiki/doc/OperationalSecurity">article 
2420)     on operational security for Tor relays</a> for more suggestions. 
2421)     </p>
2422) 
2423)     <hr>
2424) 
2425)     <a id="MoreThanOneCPU"></a>
2426)     <h3><a class="anchor" href="#MoreThanOneCPU">I have more than one CPU. 
2427)     Does this help?</a></h3>
2428) 
2429)     <p>
2430)     Yes. You can set your NumCpus config option in torrc to the number of 
2431)     CPUs you have, and Tor will spawn this many cpuworkers to deal with 
2432)     public key operations in parallel. 
2433)     </p>
2434) 
2435)     <p>
2436)     This option has no effect for clients. 
2437)     </p>
2438) 
2439)     <hr>
2440) 

2441)     <a id="HighCapacityConnection"></a>    
2442)     <h3><a class="anchor" href="#HighCapacityConnection">How can I get Tor to fully 
2443)     make use of my high capacity connection?</a></h3>
2444)     
2445)     <p>
2446)     See <a href="http://archives.seul.org/or/relays/Aug-2010/msg00034.html">this 
2447)     tor-relays thread</a>.
2448)     </p>
2449)     
2450)     <hr>    
2451)     

2452)     <a id="RelayFlexible"></a>

2453)     <h3><a class="anchor" href="#RelayFlexible">How stable does my relay
2454) need to be?</a></h3>

2455) 

2456)     <p>
2457)     We aim to make setting up a Tor relay easy and convenient:
2458)     </p>

2459) 

2460)     <ul>
2461)     <li>Tor has built-in support for <a

2462)     href="<wikifaq>#WhatbandwidthshapingoptionsareavailabletoTorrelays">

2463)     rate limiting</a>. Further, if you have a fast
2464)     link but want to limit the number of bytes per
2465)     day (or week or month) that you donate, check out the <a

2466) 
2467) href="<wikifaq>#HowcanIlimitthetotalamountofbandwidthusedbymyTorrelay">
2468) hibernation

2469)     feature</a>.
2470)     </li>

2471)     <li>Each Tor relay has an <a href="#ExitPolicies">exit policy</a>
2472) that
2473)     specifies what sort of outbound connections are allowed or refused
2474) from
2475)     that relay. If you are uncomfortable allowing people to exit from
2476) your
2477)     relay, you can set it up to only allow connections to other Tor
2478) relays.

2479)     </li>
2480)     <li>It's fine if the relay goes offline sometimes. The directories
2481)     notice this quickly and stop advertising the relay. Just try to make
2482)     sure it's not too often, since connections using the relay when it
2483)     disconnects will break.
2484)     </li>
2485)     <li>We can handle relays with dynamic IPs just fine &mdash; simply
2486)     leave the Address config option blank, and Tor will try to guess.
2487)     </li>
2488)     <li>If your relay is behind a NAT and it doesn't know its public
2489)     IP (e.g. it has an IP of 192.168.x.y), you'll need to set up port

2490)     forwarding. Forwarding TCP connections is system dependent but

2491)     <a href="#BehindANAT">this FAQ entry</a>

2492)     offers some examples on how to do this.
2493)     </li>
2494)     <li>Your relay will passively estimate and advertise its recent

2495)     bandwidth capacity, so high-bandwidth relays will attract more users
2496) than
2497)     low-bandwidth ones. Therefore having low-bandwidth relays is useful
2498) too.

2499)     </li>
2500)     </ul>

2501) 

2502)     <hr>

2503)     
2504)     <a id="BandwidthShaping"></a>
2505)     <h3><a class="anchor" href="#BandwidthShaping">What bandwidth shaping 
2506)     options are available to Tor relays?</a></h3>
2507) 
2508)     <p>
2509)     There are two options you can add to your torrc file: 
2510)     </p>
2511)     <ul>
2512)     <li>
2513)     BandwidthRate is the maximum long-term bandwidth allowed (bytes per 
2514)     second). For example, you might want to choose "BandwidthRate 2 MB" 
2515)     for 2 megabytes per second (a fast connection), or "BandwidthRate 50 
2516)     KB" for 50 kilobytes per second (a medium-speed cable connection). 
2517)     The minimum BandwidthRate is 20 kilobytes per second. 
2518)     </li>
2519)     <li>
2520)     BandwidthBurst is a pool of bytes used to fulfill requests during 
2521)     short periods of traffic above BandwidthRate but still keeps the 
2522)     average over a long period to BandwidthRate. A low Rate but a high 
2523)     Burst enforces a long-term average while still allowing more traffic 
2524)     during peak times if the average hasn't been reached lately. For example, 
2525)     if you choose "BandwidthBurst 50 KB" and also use that for your 
2526)     BandwidthRate, then you will never use more than 50 kilobytes per second; 
2527)     but if you choose a higher BandwidthBurst (like 1 MB), it will allow 
2528)     more bytes through until the pool is empty.
2529)     </li>
2530)     </ul>
2531)     <p>
2532)     If you have an asymmetric connection (upload less than download) such 
2533)     as a cable modem, you should set BandwidthRate to less than your smaller 
2534)     bandwidth (Usually that's the upload bandwidth). (Otherwise, you could 
2535)     drop many packets during periods of maximum bandwidth usage -- you may 
2536)     need to experiment with which values make your connection comfortable.) 
2537)     Then set BandwidthBurst to the same as BandwidthRate. 
2538)     </p>
2539)     <p>
2540)     Linux-based Tor nodes have another option at their disposal: they can 
2541)     prioritize Tor traffic below other traffic on their machine, so that 
2542)     their own personal traffic is not impacted by Tor load. A ​<a 
2543)     href="https://gitweb.torproject.org/tor.git/blob/HEAD:/contrib/linux-tor-prio.sh">script
2544)     to do this</a> can be found in the Tor source distribution's contrib 
2545)     directory. 
2546)     </p>
2547)     <p>
2548)     Additionally, there are hibernation options where you can tell Tor to 
2549)     only serve a certain amount of bandwidth per time period (such as 100 
2550)     GB per month). These are covered in the <a 
2551)     href="#LimitTotalBandwidth">hibernation entry</a> below. 
2552)     </p>
2553)     <p>
2554)     Note that BandwidthRate and BandwidthBurst are in <b>Bytes,</b>not Bits. 
2555)     </p>
2556) 
2557)     <hr>
2558) 
2559)     <a id="LimitTotalBandwidth"></a>
2560)     <h3><a class="anchor" href="#LimitTotalBandwidth">How can I limit the 
2561)     total amount of bandwidth used by my Tor relay?</a></h3>
2562)     <p>
2563)     The accounting options in the torrc file allow you to specify the maximum 
2564)     amount of bytes your relay uses for a time period. 
2565)     </p>
2566)     <pre>
2567)     AccountingStart day week month [day] HH:MM
2568)     </pre>
2569)     <p>
2570)     This specifies when the accounting should reset. For instance, to setup 
2571)     a total amount of bytes served for a week (that resets every Wednesday 
2572)     at 10:00am), you would use: 
2573)     </p>
2574)     <pre>
2575)     AccountingStart week 3 10:00
2576)     AccountingMax N bytes KB MB GB TB
2577)     </pre>
2578)     <p>
2579)     This specifies the maximum amount of data your relay will send during an 
2580)     accounting period, and the maximum amount of data your relay will receive 
2581)     during an account period. When the accounting period resets (from 
2582)     AccountingStart), then the counters for AccountingMax are reset to 0.
2583)     </p>
2584)     <p>
2585)     Example. Let's say you want to allow 1 GB of traffic every day in each 
2586)     direction and the accounting should reset at noon each day: 
2587)     </p>
2588)     <pre>
2589)     AccountingStart day 12:00
2590)     AccountingMax 1 GB
2591)     </pre>
2592)     <p>
2593)     Note that your relay won't wake up exactly at the beginning of each 
2594)     accounting period. It will keep track of how quickly it used its 
2595)     quota in the last period, and choose a random point in the new interval 
2596)     to wake up. This way we avoid having hundreds of relays working at the 
2597)     beginning of each month but none still up by the end. 
2598)     </p>
2599)     <p>
2600)     If you have only a small amount of bandwidth to donate compared to your 
2601)     connection speed, we recommend you use daily accounting, so you don't 
2602)     end up using your entire monthly quota in the first day. Just divide 
2603)     your monthly amount by 30. You might also consider rate limiting to 
2604)     spread your usefulness over more of the day: if you want to offer X GB 
2605)     in each direction, you could set your BandwidthRate to 20*X. For example, 
2606)     if you have 10 GB to offer each way, you might set your BandwidthRate to 
2607)     200 KB: this way your relay will always be useful for at least half of 
2608)     each day. 
2609)     </p>
2610)     <hr>

2611) 

2612)     <a id="ExitPolicies"></a>

2613)     <h3><a class="anchor" href="#ExitPolicies">I'd run a relay, but I
2614) don't want to deal with abuse issues.</a></h3>

2615) 

2616)     <p>
2617)     Great. That's exactly why we implemented exit policies.
2618)     </p>

2619) 

2620)     <p>
2621)     Each Tor relay has an exit policy that specifies what sort of

2622)     outbound connections are allowed or refused from that relay. The
2623) exit

2624)     policies are propagated to Tor clients via the directory, so clients
2625)     will automatically avoid picking exit relays that would refuse to
2626)     exit to their intended destination. This way each relay can decide
2627)     the services, hosts, and networks he wants to allow connections to,

2628)     based on abuse potential and his own situation. Read the FAQ entry
2629) on
2630)     <a href="<page docs/faq-abuse>#TypicalAbuses">issues you might
2631) encounter</a>

2632)     if you use the default exit policy, and then read Mike Perry's

2633)     <a href="<blog>tips-running-exit-node-minimal-harassment">tips

2634)     for running an exit node with minimal harassment</a>.
2635)     </p>

2636) 

2637)     <p>

2638)     The default exit policy allows access to many popular services

2639)     (e.g. web browsing), but <a

2640) href="#DefaultExitPorts">restricts</a>

2641)     some due to abuse potential (e.g. mail) and some since
2642)     the Tor network can't handle the load (e.g. default
2643)     file-sharing ports). You can change your exit policy

2644)     using Vidalia's "Sharing" tab, or by manually editing your

2645)     <a href="<page docs/faq>#torrc">torrc</a>

2646)     file. If you want to avoid most if not all abuse potential, set it
2647) to
2648)     "reject *:*" (or un-check all the boxes in Vidalia). This setting
2649) means
2650)     that your relay will be used for relaying traffic inside the Tor
2651) network,

2652)     but not for connections to external websites or other services.
2653)     </p>

2654) 

2655)     <p>

2656)     If you do allow any exit connections, make sure name resolution
2657) works

2658)     (that is, your computer can resolve Internet addresses correctly).

2659)     If there are any resources that your computer can't reach (for
2660) example,

2661)     you are behind a restrictive firewall or content filter), please

2662)     explicitly reject them in your exit policy — otherwise Tor
2663) users

2664)     will be impacted too.
2665)     </p>

2666) 

2667)     <hr>

2668) 

2669)     <a id="DifferentComputer"></a>

2670)     <h3><a class="anchor" href="#DifferentComputer">I want to run my 
2671)     Tor client on a different computer than my applications.</a></h3>

2672)     <p>

2673)     By default, your Tor client only listens for applications that 
2674)     connect from localhost. Connections from other computers are 
2675)     refused. If you want to torify applications on different computers 
2676)     than the Tor client, you should edit your torrc to define 

2677)     SocksListenAddress 0.0.0.0 and then restart (or hup) Tor. If you 

2678)     want to get more advanced, you can configure your Tor client on a 
2679)     firewall to bind to your internal IP but not your external IP.  

2680)     </p>
2681) 
2682)     <hr>
2683) 
2684)     <a id="ServerClient"></a>

2685)     <h3><a class="anchor" href="#ServerClient">Can I install Tor on a 
2686)     central server, and have my clients connect to it?</a></h3>
2687)     <p>
2688)      Yes. Tor can be configured as a client or a relay on another 
2689)      machine, and allow other machines to be able to connect to it 
2690)      for anonymity. This is most useful in an environment where many 
2691)      computers want a gateway of anonymity to the rest of the world. 
2692)      However, be forwarned that with this configuration, anyone within 
2693)      your private network (existing between you and the Tor 
2694)      client/relay) can see what traffic you are sending in clear text. 
2695)      The anonymity doesn't start until you get to the Tor relay. 
2696)      Because of this, if you are the controller of your domain and you 
2697)      know everything's locked down, you will be OK, but this configuration 
2698)      may not be suitable for large private networks where security is 
2699)      key all around.
2700)     </p>
2701)     <p>
2702) Configuration is simple, editing your torrc file's SocksListenAddress 
2703) according to the following examples:

2704)     </p>
2705)     <pre>

2706) 
2707)   #This provides local interface access only, 
2708)   #needs SocksPort to be greater than 0
2709)   SocksListenAddress 127.0.0.1 
2710) 
2711)   #This provides access to Tor on a specified interface
2712)   SocksListenAddress 192.168.x.x:9100 
2713) 
2714)   #Accept from all interfaces
2715)   SocksListenAddress 0.0.0.0:9100
2716)    </pre>

2717)     <p>

2718) You can state multiple listen addresses, in the case that you are 
2719) part of several networks or subnets.

2720)     </p>
2721)     <pre>
2722)   SocksListenAddress 192.168.x.x:9100 #eth0
2723)   SocksListenAddress 10.x.x.x:9100 #eth1
2724)     </pre>
2725)     <p>

2726) After this, your clients on their respective networks/subnets would specify 
2727) a socks proxy with the address and port you specified SocksListenAddress 
2728) to be. 

2729)     </p>
2730)     <p>

2731) Please note that the SocksPort configuration option gives the port ONLY for 
2732) localhost (127.0.0.1). When setting up your SocksListenAddress(es), you need 
2733) to give the port with the address, as shown above.

2734)     <p>

2735) If you are interested in forcing all outgoing data through the central Tor 
2736) client/relay, instead of the server only being an optional proxy, you may find 
2737) the program iptables (for *nix) useful. 

2738)     </p>
2739) 
2740)     <hr>
2741) 

2742)     <a id="JoinTheNetwork"></a>

2743)     <h3><a class="anchor" href="#JoinTheNetwork">So I can just configure a 
2744)     nickname and ORPort and join the network?</a></h3>

2745) 
2746)     <p>

2747)      Yes. You can join the network and be a useful relay just by configuring 
2748)      your Tor to be a relay and making sure it's reachable from the outside.

2749)     </p>
2750)     <p>
2751) 30 Seconds to a Tor Relay:
2752)     </p>
2753)     <ul><li>
2754)     Configure a Nickname: 
2755)     </li></ul>
2756)     <pre>
2757) Nickname ididnteditheconfig
2758)     </pre>

2759)     <ul><li>

2760)     Configure ORPort: 

2761)     </li></ul>

2762)     <pre>
2763) ORPort 9001
2764)     </pre>

2765)     <ul><li>

2766)     Configure Contact Info: 

2767)     </li></ul>

2768) 
2769)     <pre>
2770) ContactInfo human@…

2771)     </pre>
2772)     <ul><li>

2773)     Start Tor. Watch the log file for a log entry that states: "Self-testing 
2774)     indicates your ORPort is reachable from the outside. Excellent. Publishing 
2775)     server descriptor."

2776)     </li></ul>

2777) 
2778)     <hr />

2779) 

2780)     <a id="RelayOrBridge"></a>

2781)     <h3><a class="anchor" href="#RelayOrBridge">Should I be a normal
2782) relay or bridge relay?</a></h3>

2783) 

2784)     <p><a href="<page docs/bridges>">Bridge relays</a> (or "bridges" for
2785) short)
2786)     are <a href="<page docs/tor-doc-relay>">Tor relays</a> that aren't

2787)     listed in the public Tor directory.

2788)     That means that ISPs or governments trying to block access to the

2789)     Tor network can't simply block all bridges.

2790)     </p>

2791) 

2792)     <p>Being a normal relay vs being a bridge relay is almost the same
2793)     configuration: it's just a matter of whether your relay is listed

2794)     publicly or not.

2795)     </p>

2796) 

2797)     <p>

2798)     So bridges are useful a) for Tor users in oppressive regimes,

2799)     and b) for people who want an extra layer of security

2800)     because they're worried somebody will recognize that it's a public
2801)     Tor relay IP address they're contacting.

2802)     </p>

2803) 

2804)     <p>
2805)     Several countries, including China and Iran, have found ways to

2806)     detect and block connections to Tor bridges.

2807)     <a href="<page projects/obfsproxy>">Obfsproxy</a> bridges address

2808)     this by adding another layer of obfuscation.

2809)     </p>
2810) 

2811)     <p>So should you run a normal relay or bridge relay? If you have
2812) lots

2813)     of bandwidth, you should definitely run a normal relay.
2814)     If you're willing

2815)     to <a href="#ExitPolicies">be an exit</a>, you should definitely
2816)     run a normal relay, since we need more exits. If you can't be an
2817)     exit and only have a little bit of bandwidth, be a bridge. Thanks
2818)     for volunteering!

2819)     </p>

2820) 

2821)     <hr>

2822) 

2823) <a id="UpgradeOrMove"></a>

2824) <h3><a class="anchor" href="#UpgradeOrMove">I want to upgrade/move my relay. 
2825) How do I keep the same key?</a></h3>

2826) 
2827) <p>

2828)  When upgrading your Tor relay, or running it on a different computer, 
2829)  the important part is to keep the same nickname (defined in your torrc 
2830)  file) and the same identity key (stored in "keys/secret_id_key" in 
2831)  your DataDirectory).

2832) </p>
2833) <p>

2834) This means that if you're upgrading your Tor relay and you keep the same 
2835) torrc and the same DataDirectory, then the upgrade should just work and 
2836) your relay will keep using the same key. If you need to pick a new 
2837) DataDirectory, be sure to copy your old keys/secret_id_key over. 

2838) </p>
2839) 
2840)     <hr>
2841) 
2842) <a id="NTService"></a>

2843) <h3><a class="anchor" href="#NTService">How do I run my Tor relay as an NT 
2844) service?</a></h3>

2845) 
2846) <p>

2847)  You can run Tor as a service on all versions of Windows except Windows 
2848)  95/98/ME. This way you can run a Tor relay without needing to always have 
2849)  Vidalia running.

2850) </p>
2851) <p>

2852) If you've already configured your Tor to be a relay, please note that when 
2853) you enable Tor as a service, it will use a different DatagDirectory, and 
2854) thus will generate a different key. If you want to keep using the old key, 
2855) see the Upgrading your Tor relay FAQ entry for how to restore the old 
2856) identity key.

2857) </p>
2858) <p>
2859) To install Tor as a service, you can simply run:
2860) </p>
2861) <pre>
2862) tor --service install
2863) </pre>
2864) <p>

2865) A service called Tor Win32 Service will be installed and started. This 
2866) service will also automatically start every time Windows boots, unless 
2867) you change the Start-up type. An easy way to check the status of Tor, 
2868) start or stop the service, and change the start-up type is by running 
2869) services.msc and finding the Tor service in the list of currently 
2870) installed services.

2871) </p>
2872) <p>

2873) Optionally, you can specify additional options for the Tor service using 
2874) the -options argument. For example, if you want Tor to use C:\tor\torrc, 
2875) instead of the default torrc, and open a control port on port 9151, you 
2876) would run:

2877) </p>
2878) <pre>
2879) tor --service install -options -f C:\tor\torrc ControlPort 9151
2880) </pre>
2881) <p>
2882) You can also start or stop the Tor service from the command line by typing:
2883) </p>
2884) <pre>
2885)  tor --service start
2886) </pre>
2887) <p>
2888) or
2889) </p>
2890) <pre>
2891)  tor --service stop
2892) </pre>
2893) <p>
2894) To remove the Tor service, you can run the following command:
2895) </p>
2896) <pre>
2897) tor --service remove
2898) </pre>
2899) <p>

2900) If you are running Tor as a service and you want to uninstall Tor entirely, 
2901) be sure to run the service removal command (shown above) first before 
2902) running the uninstaller from "Add/Remove Programs". The uninstaller is 
2903) currently not capable of removing the active service.

2904) </p>
2905) 
2906) <hr>
2907) 
2908) <a id="VirtualServer"></a>

2909) <h3><a class="anchor" href="#VirtualServer">Can I run a Tor relay from my 
2910) virtual server account?</a></h3>

2911) 
2912) <p>

2913) Some ISPs are selling "vserver" accounts that provide what they call a 
2914) virtual server -- you can't actually interact with the hardware, and 
2915) they can artificially limit certain resources such as the number of file 
2916) descriptors you can open at once. Competent vserver admins are able to 
2917) configure your server to not hit these limits. For example, in SWSoft's 
2918) Virtuozzo, investigate /proc/user_beancounters. Look for "failcnt" in 
2919) tcpsndbuf, tcprecvbuf, numothersock, and othersockbuf. Ask for these to 
2920) be increased accordingly. Some users have seen settings work well as follows: 

2921) <p>

2922) <table border="1">

2923) <tr>
2924) <td>
2925) <i>resource</i>
2926) </td>
2927) <td>
2928) <i>held</i>
2929) </td>
2930) <td>
2931) <i>maxheld</i>
2932) </td>
2933) <td>
2934) <i>barrier</i>
2935) </td>
2936) <td>
2937) <i>limit</i>
2938) </td>
2939) <td>
2940) <i>failcnt</i>
2941) </td>
2942) </tr>
2943) <tr>
2944) <td>
2945) tcpsndbuf
2946) </td>
2947) <td>
2948) 46620
2949) </td>
2950) <td>
2951) 48840
2952) </td>
2953) <td>
2954) 3440640
2955) </td>
2956) <td>
2957) 5406720
2958) </td>
2959) <td>
2960) 0
2961) </td>
2962) </tr>
2963) <tr>
2964) <td>
2965) tcprcvbuf
2966) </td>
2967) <td>
2968) 0
2969) </td>
2970) <td>
2971) 2220
2972) </td>
2973) <td>
2974) 3440640
2975) </td>
2976) <td>
2977) 5406720
2978) </td>
2979) <td>
2980) 0
2981) </td>
2982) </tr>
2983) <tr>
2984) <td>
2985) othersockbuf
2986) </td>
2987) <td>
2988) 243516
2989) </td>
2990) <td>
2991) 260072
2992) </td>
2993) <td>
2994) 2252160
2995) </td>
2996) <td>
2997) 4194304
2998) </td>
2999) <td>
3000) 0
3001) </td>
3002) </tr>
3003) <tr>
3004) <td>
3005) numothersock
3006) </td>
3007) <td>
3008) 151
3009) </td>
3010) <td>
3011) 153
3012) </td>
3013) <td>
3014) 720
3015) </td>
3016) <td>
3017) 720
3018) </td>
3019) <td>
3020) 0
3021) </td>
3022) </tr>
3023) </table>
3024) <p>
3025)  Xen, Virtual Box and VMware virtual servers have no such limits normally.
3026) </p>
3027) <p>

3028) If the vserver admin will not increase system limits another option is 
3029) to reduce the memory allocated to the send and receive buffers on TCP 
3030) connections Tor uses. An experimental feature to constrain socket buffers 
3031) has recently been added. If your version of Tor supports it, set 
3032) "ConstrainedSockets 1" in your configuration. See the tor man page for 
3033) additional details about this option.

3034) </p>
3035) <p>

3036) Unfortunately, since Tor currently requires you to be able to connect to 
3037) all the other Tor relays, we need you to be able to use at least 1024 file 
3038) descriptors. This means we can't make use of Tor relays that are crippled 
3039) in this way.

3040) </p>
3041) <p>

3042) We hope to fix this in the future, once we know how to build a Tor network 
3043) with restricted topologies -- that is, where each node connects to only a 
3044) few other nodes. But this is still a long way off.

3045) </p>
3046) 

3047) <hr>
3048) 

3049) <a id="MultipleRelays"></a>

3050) <h3><a class="anchor" href="#MultipleRelays">I want to run more than one
3051) relay.</a></h3>

3052) 
3053) <p>
3054) Great. If you want to run several relays to donate more to the network,
3055) we're happy with that. But please don't run more than a few dozen on
3056) the same network, since part of the goal of the Tor network is dispersal
3057) and diversity.
3058) </p>
3059) 
3060) <p>
3061) If you do decide to run more than one relay, please set the "MyFamily"

3062) config option in the <a href="#torrc">torrc</a> of each relay, listing
3063) all the relays (comma-separated) that are under your control:

3064) </p>
3065) 
3066) <pre>
3067)     MyFamily $fingerprint1,$fingerprint2,$fingerprint3
3068) </pre>
3069) 
3070) <p>
3071) where each fingerprint is the 40 character identity fingerprint (without

3072) spaces). You can also list them by nickname, but fingerprint is safer.
3073) Be

3074) sure to prefix the digest strings with a dollar sign ('$') so that the
3075) digest is not confused with a nickname in the config file.
3076) </p>
3077) 
3078) <p>
3079) That way clients will know to avoid using more than one of your relays
3080) in a single circuit. You should set MyFamily if you have administrative
3081) control of the computers or of their network, even if they're not all in
3082) the same geographic location.
3083) </p>
3084) 
3085)     <hr>
3086) 

3087)     <a id="WrongIP"></a>

3088)     <h3><a class="anchor" href="#WrongIP">My relay is picking the wrong 
3089)     IP address.</a></h3>

3090)     <p>

3091)  Tor guesses its IP address by asking the computer for its hostname, and 
3092)  then resolving that hostname. Often people have old entries in their 
3093)  /etc/hosts file that point to old IP addresses.

3094)     </p>
3095)     <p>

3096) If that doesn't fix it, you should use the "Address" config option to 
3097) specify the IP you want it to pick. If your computer is behind a NAT and 
3098) it only has an internal IP address, see the following FAQ entry on <a 

3099) href="#RelayFlexible">dynamic IP addresses</a>.

3100)     </p>
3101)     <p>

3102) Also, if you have many addresses, you might also want to set 
3103) "OutboundBindAddress" so external connections come from the IP you intend 
3104) to present to the world. 

3105)     </p>
3106) 
3107)     <hr>
3108) 
3109)     <a id="BehindANAT"></a>
3110)     <h3><a class="anchor" href="#BehindANAT">I'm behind a NAT/Firewall.</a></h3>
3111) 
3112)     <p>

3113) See <a>​http://portforward.com/</a> for directions on how to port forward with 
3114) your NAT/router device.

3115) </p>
3116) <p>

3117) If your relay is running on a internal net you need to setup port forwarding. 
3118) Forwarding TCP connections is system dependent but the firewalled-clients FAQ 
3119) entry offers some examples on how to do this.

3120) </p>
3121) <p>

3122) Also, here's an example of how you would do this on GNU/Linux if you're using 
3123) iptables:

3124) </p>
3125) <pre>
3126) /sbin/iptables -A INPUT -i eth0 -p tcp --destination-port 9001 -j ACCEPT
3127) </pre>
3128) <p>

3129) You may have to change "eth0" if you have a different external interface 
3130) (the one connected to the Internet). Chances are you have only one (except 
3131) the loopback) so it shouldn't be too hard to figure out. 

3132)     </p>
3133)     <hr>
3134) 

3135)     <a id="RelayMemory"></a>

3136)     <h3><a class="anchor" href="#RelayMemory">Why is my Tor relay using
3137) so much memory?</a></h3>

3138) 

3139)     <p>If your Tor relay is using more memory than you'd like, here are
3140) some

3141)     tips for reducing its footprint:
3142)     </p>

3143) 

3144)     <ol>
3145)     <li>If you're on Linux, you may be encountering memory fragmentation

3146)     bugs in glibc's malloc implementation. That is, when Tor releases
3147) memory
3148)     back to the system, the pieces of memory are fragmented so they're
3149) hard
3150)     to reuse. The Tor tarball ships with OpenBSD's malloc
3151) implementation,
3152)     which doesn't have as many fragmentation bugs (but the tradeoff is
3153) higher
3154)     CPU load). You can tell Tor to use this malloc implementation
3155) instead:

3156)     <tt>./configure --enable-openbsd-malloc</tt></li>

3157) 

3158)     <li>If you're running a fast relay, meaning you have many TLS
3159) connections

3160)     open, you are probably losing a lot of memory to OpenSSL's internal
3161)     buffers (38KB+ per socket). We've patched OpenSSL to <a

3162) 
3163) href="https://lists.torproject.org/pipermail/tor-dev/2008-June/001519.
3164) html">release

3165)     unused buffer memory more aggressively</a>. If you update to OpenSSL

3166)     1.0.0 or newer, Tor's build process will automatically recognize and
3167) use

3168)     this feature.</li>

3169) 

3170) <!-- Nickm says he's not sure this is still accurate
3171) 

3172)     <li>If you're running on Solaris, OpenBSD, NetBSD, or
3173)     old FreeBSD, Tor is probably forking separate processes
3174)     rather than using threads. Consider switching to a <a
3175)     href="<wikifaq>#WhydoesntmyWindowsorotherOSTorrelayrunwell">better
3176)     operating system</a>.</li>

3177) -->

3178)     <li>If you still can't handle the memory load, consider reducing the

3179)     amount of bandwidth your relay advertises. Advertising less
3180) bandwidth

3181)     means you will attract fewer users, so your relay shouldn't grow
3182)     as large. See the <tt>MaxAdvertisedBandwidth</tt> option in the man
3183)     page.</li>

3184) 

3185)     </ol>

3186) 

3187)     <p>

3188)     All of this said, fast Tor relays do use a lot of ram. It is not
3189) unusual

3190)     for a fast exit relay to use 500-1000 MB of memory.
3191)     </p>

3192) 

3193)     <hr>

3194) 

3195)     <a id="BetterAnonymity"></a>

3196)     <h3><a class="anchor" href="#BetterAnonymity">Do I get better anonymity 
3197)     if I run a relay?</a></h3>

3198) 

3199)     <p>

3200) Yes, you do get better anonymity against some attacks.
3201)     </p>
3202)     <p>

3203) The simplest example is an attacker who owns a small number of Tor relays. 
3204) He will see a connection from you, but he won't be able to know whether 
3205) the connection originated at your computer or was relayed from somebody else.

3206)     </p>
3207)     <p>

3208) There are some cases where it doesn't seem to help: if an attacker can 
3209) watch all of your incoming and outgoing traffic, then it's easy for him 
3210) to learn which connections were relayed and which started at you. (In 
3211) this case he still doesn't know your destinations unless he is watching 
3212) them too, but you're no better off than if you were an ordinary client.)

3213)     </p>
3214)     <p>

3215) There are also some downsides to running a Tor relay. First, while we 
3216) only have a few hundred relays, the fact that you're running one might 
3217) signal to an attacker that you place a high value on your anonymity. 
3218) Second, there are some more esoteric attacks that are not as 
3219) well-understood or well-tested that involve making use of the knowledge 
3220) that you're running a relay -- for example, an attacker may be able to 
3221) "observe" whether you're sending traffic even if he can't actually watch 
3222) your network, by relaying traffic through your Tor relay and noticing 
3223) changes in traffic timing.

3224)     </p>
3225)     <p>

3226) It is an open research question whether the benefits outweigh the risks. 
3227) A lot of that depends on the attacks you are most worried about. For 
3228) most users, we think it's a smart move. 

3229)     </p>

3230) 

3231)     <hr>

3232) 

3233)     <a id="RelayDonations"></a>

3234)     <h3><a class="anchor" href="#RelayDonations">Can I donate for a
3235)     relay rather than run my own?</a></h3>