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

34)     <li><a href="#IsItWorking">How can I tell if Tor is working, and that my

35)     connections really are anonymized?</a></li>

36)     <li><a href="#Mobile">Can I use Tor on my phone or mobile device?</a></li>

37)     <li><a href="#OutboundPorts">Which outbound ports must be open when
38)     using Tor as a client?</a></li>

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

40)     <li><a href="#NoDataScrubbing">Does Tor remove personal information

41)     from the data my application sends?</a></li>

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

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

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

46)     </ul>

47) 

48)     <p>Compilation and Installation:</p>

49) 

50)     <ul>
51)     <li><a href="#HowUninstallTor">How do I uninstall Tor?</a></li>
52)     <li><a href="#PGPSigs">What are these "sig" files on the download
53)     page?</a></li>

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

56)     <li><a href="#VirusFalsePositives">Why does my Tor executable appear to

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

58)     <li><a href="#tarballs">How do I open a .tar.gz or .tar.xz file?</a></li>

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

61)     </ul>

62) 

63)     <p>Tor Browser (general):</p>

64)     <ul>

65) 

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

68)     <li><a href="#Ubuntu">I'm using Ubuntu, and I can't start Tor Browser.

69)     </a></li>

70)     <li><a href="#SophosOnMac">I'm using the Sophos anti-virus

71)     software on my Mac, and Tor starts but I can't browse anywhere.</a></li>

72)     <li><a href="#XPCOMError">When I start Tor Browser I get an 
73) error message: "Cannot load XPCOM".</a></li>

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

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

76)     <li><a href="#TBBJavaScriptEnabled">Why is NoScript configured to

77) allow JavaScript by default in Tor Browser?  Isn't that

78) unsafe?</a></li>

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

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

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

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

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

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

87)     <li><a href="#NeedToUseAProxy">My internet connection requires an HTTP

88)     or SOCKS Proxy</a></li>

89)     <li><a href="#TBBSocksPort">I want to
90)     run another application through Tor.</a></li>

91)     <li><a href="#CantSetProxy">What should I do if I can't set a proxy

92)     with my application?</a></li>

93)     </ul>
94) 

95)     <p>Tor Browser (3.x and later):</p>

96) 
97)     <ul>

98)     <li><a href="#DisableJS">How do I disable JavaScript?</a></li>

99)     <li><a href="#VerifyDownload">How do I verify the download

100)     (sha256sums.txt)?</a></li>

101)     <li><a href="#NewIdentityClosingTabs">Why does "New Identity" close

102)     all my open tabs?</a></li>

103)     <li><a href="#ConfigureRelayOrBridge">How do I configure Tor as a relay

104)     or bridge?</a></li>
105)     <li><a href="#Timestamps">Why are the file timestamps from 2000?</a></li>

106)     <li><a href="#TBBSourceCode">Where is the source code for Tor Browser?

107)     How do I verify a build?</a></li>

108)     </ul>
109) 

110)     <p>Advanced Tor usage:</p>

111) 

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

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

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

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

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

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

133) 

134)     <p>Running a Tor relay:</p>

135)     <ul>

136) 
137)     <li><a href="#HowDoIDecide">How do I decide if I should run a relay?
138)     </a></li>

139)     <li><a href="#WhyIsntMyRelayBeingUsedMore">Why isn't my relay being

140)     used more?</a></li>

141)     <li><a href="#IDontHaveAStaticIP">I don't have a static IP.</a></li>

142)     <li><a href="#PortscannedMore">Why do I get portscanned more often

143)     when I run a Tor relay?</a></li>

144)     <li><a href="#HighCapacityConnection">How can I get Tor to fully

145)     make use of my high capacity connection?</a></li>

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

148)     <li><a href="#BandwidthShaping">What bandwidth shaping options are

149)     available to Tor relays?</a></li>

150)     <li><a href="#LimitTotalBandwidth">How can I limit the total amount

151)     of bandwidth used by my Tor relay?</a></li>

152)     <li><a href="#RelayWritesMoreThanItReads">Why does my relay write

153)     more bytes onto the network than it reads?</a></li>

154)     <li><a href="#Hibernation">Why can I not browse anymore after

155)     limiting bandwidth on my Tor relay?</a></li>

156)     <li><a href="#ExitPolicies">I'd run a relay, but I don't want to deal

157)     with abuse issues.</a></li>

158)     <li><a href="#BestOSForRelay">Why doesn't my Windows (or other OS) Tor

159)     relay run well?</a></li>

160)     <li><a href="#PackagedTor">Should I install Tor from my package manager,

161)     or build from source?</a></li>

162)     <li><a href="#WhatIsTheBadExitFlag">What is the BadExit flag?</a></li>

163)     <li><a href="#IGotTheBadExitFlagWhyDidThatHappen">I got the BadExit flag.

164)     Why did that happen?</a></li>

165)     <li><a href="#MyRelayRecentlyGotTheGuardFlagAndTrafficDroppedByHalf">My

166)     relay recently got the Guard flag and traffic dropped by half.</a></li>

167)     <li><a href="#TorClientOnADifferentComputerThanMyApplications">I want to run my Tor client on a

168)     different computer than my applications.</a></li>

169)     <li><a href="#ServerClient">Can I install Tor on a central server, and

170)     have my clients connect to it?</a></li>

171)     <li><a href="#JoinTheNetwork">So I can just configure a nickname and

172)     ORPort and join the network?</a></li>

173)     <li><a href="#RelayOrBridge">Should I be a normal relay or bridge
174)     relay?</a></li>

175)     <li><a href="#UpgradeOrMove">I want to upgrade/move my relay. How do I

176)     keep the same key?</a></li>

177)     <li><a href="#OfflineED25519">How do offline ed25519 identity keys work?
178)     What do I need to know?</a></li>

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

181)     <li><a href="#NTService">How do I run my Tor relay as an NT service?
182)     </a></li>

183)     <li><a href="#VirtualServer">Can I run a Tor relay from my virtual server

184)     account?</a></li>

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

187)     <li><a href="#OutgoingFirewall">How should I configure the outgoing filters on my relay?</a></li>

188)     <li><a href="#RelayMemory">Why is my Tor relay using so much memory?
189)     </a></li>
190)     <li><a href="#BetterAnonymity">Do I get better anonymity if I run a relay?
191)     </a></li>

192)     <li><a href="#FacingLegalTrouble">I'm facing legal trouble. How do I

193)     prove that my server was a Tor relay at a given time?</a></li>

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

196)     </ul>

197) 

198)     <p>Tor hidden services:</p>

199) 

200)     <ul>
201)     <li><a href="#AccessHiddenServices">How do I access hidden services?</a></li>

202)     <li><a href="#ProvideAHiddenService">How do I provide a hidden service?</a></li>

203)     </ul>

204) 

205)     <p>Development:</p>

206) 

207)     <ul>

208)     <li><a href="#VersionNumbers">What do these weird version numbers

209)     mean?</a></li>
210)     <li><a href="#PrivateTorNetwork">How do I set up my own private
211)     Tor network?</a></li>

212)     <li><a href="#UseTorWithJava">How can I make my Java program use the

213)     Tor network?</a></li>
214)     <li><a href="#WhatIsLibevent">What is Libevent?</a></li>

215)     <li><a href="#MyNewFeature">What do I need to do to get a new feature

216)     into Tor?</a></li>
217)     </ul>
218) 

219)     <p>Anonymity and Security:</p>

220)     <ul>

221)     <li><a href="#WhatProtectionsDoesTorProvide">What protections does Tor

222)     provide?</a></li>

223)     <li><a href="#CanExitNodesEavesdrop">Can exit nodes eavesdrop on

224)     communications? Isn't that bad? </a></li>

225)     <li><a href="#AmITotallyAnonymous">So I'm totally anonymous if I use

226)     Tor?</a></li>

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

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

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

231)     <li><a href="#CellSize">Tor uses hundreds of bytes for every IRC line. I

232)     can't afford that!</a></li>

233)     <li><a href="#OutboundConnections">Why does netstat show these outbound

234)     connections?</a></li>
235)     <li><a href="#PowerfulBlockers">What about powerful blocking mechanisms
236)     </a></li>

237)     <li><a href="#RemotePhysicalDeviceFingerprinting">Does Tor resist

238)     "remote physical device fingerprinting"?</a></li>

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

240)     <li><a href="#Proxychains">Aren't 10 proxies (proxychains) better than

241)     Tor with only 3 hops?</a></li>

242)     <li><a href="#AttacksOnOnionRouting">What attacks remain against onion

243)     routing?</a></li>

244)     <li><a href="#LearnMoreAboutAnonymity">Where can I learn more about anonymity?</a></li>

245)     </ul>

246) 

247)     <p>Alternate designs that we don't do (yet):</p>

248) 

249)     <ul>
250)     <li><a href="#EverybodyARelay">You should make every Tor user be a
251)     relay.</a></li>

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

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

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

257)     <li><a href="#ChoosePathLength">You should let people choose their path

258)     length.</a></li>

259)     <li><a href="#SplitEachConnection">You should split each connection over

260)     many paths.</a></li>

261)     <li><a href="#MigrateApplicationStreamsAcrossCircuits">You should migrate

262)     application streams across circuits.</a></li>

263)     <li><a href="#LetTheNetworkPickThePath">You should let the network pick

264)     the path, not the client.</a></li>

265)     <li><a href="#UnallocatedNetBlocks">Your default exit policy should block

266)     unallocated net blocks too.</a></li>

267)     <li><a href="#BlockWebsites">Exit policies should be able to block

268)     websites, not just IP addresses.</a></li>

269)     <li><a href="#BlockContent">You should change Tor to prevent users from

270)     posting certain content.</a></li>

271)     <li><a href="#SendPadding">You should send padding so it's more secure.
272)     </a></li>

273)     <li><a href="#Steganography">You should use steganography to hide Tor

274)     traffic.</a></li>

275)     </ul>

276) 

277)     <p>Abuse:</p>

278)     <ul>

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

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

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

285)     </ul>

286) 

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

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

290) 

291)     <hr>

292) 

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

294)     <h2><a class="anchor">General:</a></h2>

295) 

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

298) 

299)     <p>
300)     The name "Tor" can refer to several different components.
301)     </p>

302) 

303)     <p>

304)     Tor is a program you can run on your computer that helps keep
305)     you safe on the Internet. It protects you by bouncing your communications

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

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

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

309)     from learning your physical location.
310)     This set of volunteer relays is called the <b>Tor network</b>.
311)     The way most people use Tor is with <b>Tor Browser</b>,
312)     which is a version of Firefox that fixes many privacy issues.
313)     You can read more about how Tor works on the <a href="<page
314)     about/overview>">overview page</a>.

315)     </p>

316) 

317)     <p>

318)     The <b>Tor Project</b> is a non-profit (charity) organization that
319)     maintains and develops the Tor software.

320)     </p>

321) 

322)     <hr>

323) 

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

325)     <h3><a class="anchor" href="#Torisdifferent">How is Tor different
326) from other proxies?</a></h3>
327)     <p>
328)     A typical proxy provider sets up a server somewhere on the Internet
329) and
330) allows you to use it to relay your traffic.  This creates a simple, easy
331) to
332) maintain architecture.  The users all enter and leave through the same
333) server.
334) The provider may charge for use of the proxy, or fund their costs
335) through
336) advertisements on the server.  In the simplest configuration, you don't
337) have to
338) install anything.  You just have to point your browser at their proxy
339) server.
340) Simple proxy providers are fine solutions if you do not want protections
341) for

342) your privacy and anonymity online and you trust the provider to not do

343) bad
344) things.  Some simple proxy providers use SSL to secure your connection

345) to them, which protects you against local eavesdroppers, such as those at a
346) cafe with free wifi Internet.

347)     </p>
348)     <p>

349)     Simple proxy providers also create a single point of failure.  The
350) provider

351) knows both who you are and what you browse on the Internet.  They can see

352) your
353) traffic as it passes through their server.  In some cases, they can even
354) see

355) inside your

356) encrypted traffic as they relay it to your banking site or to ecommerce
357) stores.

358) You have to trust the provider isn't

359) watching your traffic, injecting their own advertisements into your
360) traffic

361) stream, or recording your personal details.

362)     </p>
363)     <p>

364)     Tor passes your traffic through at least 3 different servers before
365) sending
366) it on to the destination. Because there's a separate layer of encryption
367) for

368) each of the three relays, somebody watching your Internet connection
369) can't modify, or read, what you are
370) sending into the Tor network. Your traffic is encrypted between the Tor
371) client (on your computer) and where it pops out somewhere else in the
372) world.
373) </p>

374)     <p>
375)     <dl>

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

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

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

391) this traffic.  If you're using encryption (like
392) HTTPS), it will only know the destination. See <a
393) href="https://www.eff.org/pages/tor-and-https">this visualization of
394) Tor and HTTPS</a> to understand how Tor and HTTPS interact.
395) </dd>

396)     </dl>
397)     </p>

398) 

399)     <hr>

400) 

401) 

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

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

405) 

406)     <p>

407)     Most people use Tor Browser,

408)     which includes everything you need to browse the web safely using

409)     Tor. Using other browsers is <a href="#TBBOtherBrowser">dangerous
410)     and not recommended</a>.

411)     </p>
412)     <p>
413)     There are plenty of other programs you can use with Tor,
414)     but we haven't researched the application-level anonymity

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

416)     configuration. Our wiki has a community-maintained list of
417)     instructions for <a

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

419)     specific applications</a>.

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

422) 

423)     <hr>

424) 

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

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

428) 

429)     <p>
430)     Because Tor is the onion routing network. When we were starting the
431)     new next-generation design and implementation of onion routing in
432)     2001-2002, we would tell people we were working on onion routing,
433)     and they would say "Neat. Which one?" Even if onion routing has
434)     become a standard household term, Tor was born out of the actual <a
435)     href="http://www.onion-router.net/">onion routing project</a> run by
436)     the Naval Research Lab.
437)     </p>

438) 

439)     <p>
440)     (It's also got a fine translation from German and Turkish.)
441)     </p>

442) 

443)     <p>

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

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

447)     spot people who haven't read any of our website (and have instead
448) learned
449)     everything they know about Tor from news articles) by the fact that
450) they

451)     spell it wrong.
452)     </p>

453) 

454)     <hr>

455) 

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

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

459) 

460)     <p>

461)     There is absolutely no backdoor in Tor.  We know some smart lawyers
462)     who say that it's unlikely that anybody will try to make us add one
463)     in our jurisdiction (U.S.). If they do ask us, we will fight them,
464)     and (the lawyers say) probably win.

465)     </p>

466) 

467)     <p>

468)     We will <a
469)     href="https://media.ccc.de/v/31c3_-_6251_-_en_-_saal_1_-_201412301400_-_state_of_the_onion_-_jacob_-_arma">never</a>
470)     put a backdoor in Tor.

471)     We think that putting a backdoor in Tor would be tremendously

472)     irresponsible to our users, and a bad precedent for security

473)     software in general. If we ever put a deliberate backdoor in our
474)     security software, it would ruin our professional reputations.
475)     Nobody would trust our software ever again — for excellent
476)     reason!

477)     </p>

478) 

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

482)     computers, or something like that. Tor is open source, and you

483)     should always check the source (or at least the diffs since the last
484)     release) for suspicious things. If we (or the distributors) don't
485)     give you source, that's a sure sign something funny might be going
486)     on. You should also check the <a href="<page
487)     docs/verifying-signatures>">PGP signatures</a> on the releases, to
488)     make sure nobody messed with the distribution sites.

489)     </p>

490) 

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

493)     anonymity. We periodically find and fix anonymity-related bugs, so

494)     make sure you keep your Tor versions up-to-date.

495)     </p>

496) 

497)     <hr>

498) 

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

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

502) 

503)     <p>
504)     Yes.
505)     </p>

506) 

507)     <p>

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

511)     ask us for specific permission.
512)     </p>

513) 

514)     <p>

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

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

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

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

520) 

521)     <p>

522)     Most people who ask us this question don't want to distribute just 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/organizations/">Firefox

526)     Extended Support Release</a>, and the NoScript and HTTPS-Everywhere
527)     extensions. You will need to follow the license for those programs as
528)     well. Both of those Firefox extensions are distributed under

529)     the <a href="https://www.fsf.org/licensing/licenses/gpl.html">GNU General

530)     Public License</a>, while Firefox ESR is released under the Mozilla Public
531)     License. The simplest way to obey their licenses is to include the source
532)     code for these programs everywhere you include the bundles themselves.

533)     </p>

534) 

535)     <p>

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

539)     </p>

540) 

541)     <hr>

542) 

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

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

546) 

547)     <p>See the <a href="<page about/contact>#support">Support section
548)     on the contact page</a>.

549) 

550)     <hr>

551) 

552)     <a id="Forum"></a>
553)     <h3><a class="anchor" href="#Forum">Is there a Tor forum?</a></h3>
554) 

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

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

557)     </p>
558) 
559)     <hr>
560) 

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

563) 

564)     <p>
565)     There are many reasons why the Tor network is currently slow.
566)     </p>

567) 

568)     <p>

569)     Before we answer, though, you should realize that Tor is never going
570) to
571)     be blazing fast. Your traffic is bouncing through volunteers'
572) computers
573)     in various parts of the world, and some bottlenecks and network
574) latency

575)     will always be present. You shouldn't expect to see university-style
576)     bandwidth through Tor.
577)     </p>

578) 

579)     <p>

580)     But that doesn't mean that it can't be improved. The current Tor
581) network
582)     is quite small compared to the number of people trying to use it,
583) and
584)     many of these users don't understand or care that Tor can't
585) currently

586)     handle file-sharing traffic load.
587)     </p>

588) 

589)     <p>
590)     For the much more in-depth answer, see <a

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

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

594)     to go with it.
595)     </p>

596) 

597)     <p>
598)     What can you do to help?
599)     </p>

600) 

601)     <ul>

602) 

603)     <li>

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

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

610) 

611)     <li>

612)     Help us make Tor more usable. We

613)     especially need people to help make it easier to configure your Tor
614)     as a relay. Also, we need help with clear simple documentation to
615)     walk people through setting it up.
616)     </li>

617) 

618)     <li>

619)     There are some bottlenecks in the current Tor network. Help us
620) design
621)     experiments to track down and demonstrate where the problems are,
622) and

623)     then we can focus better on fixing them.
624)     </li>

625) 

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

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

632)     get to spend more time on it.
633)     </li>

634) 

635)     <li>

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

640)     getinvolved/volunteer>">look at our volunteer page</a>.
641)     </li>

642) 

643)     <li>

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

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

647)     competition's websites discreetly, or to connect back to the home
648) servers
649)     when on the road without revealing affiliations? If your
650) organization has
651)     an interest in keeping the Tor network working, please contact them
652) about
653)     supporting Tor. Without sponsors, Tor is going to become even
654) slower.

655)     </li>

656) 

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

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

661)     cause</a>. It adds up!
662)     </li>

663) 

664)     </ul>

665) 

666)     <hr>

667) 

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

669)     <h3><a class="anchor" href="#FileSharing">How can I share files

670)     anonymously through Tor?</a></h3>

671) 
672)     <p>

673)     File sharing (peer-to-peer/P2P) is widely unwanted in the Tor network,
674)     and exit nodes are configured to block file sharing traffic by default.
675)     Tor is not really designed for it, and file sharing through Tor slows
676)     down everyone's browsing. Also, Bittorrent over Tor <a

677)     href="https://blog.torproject.org/blog/bittorrent-over-tor-isnt-good-idea">
678)     is not anonymous</a>!

679)     </p>
680) 
681)     <hr>
682) 

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

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

686) 

687)     <p>

688)     The Tor network's <a

689) 
690) href="https://metrics.torproject.org/network.html#networksize">several

691)     thousand</a> relays push <a
692)     href="https://metrics.torproject.org/network.html#bandwidth">over

693)     7.5GB per second on average</a>. We have <a

694) 

695) href="https://metrics.torproject.org/users.html#direct-users">millions of
696)     daily users</a>. But the Tor network is not yet

697)     self-sustaining.

698)     </p>

699) 

700)     <p>

701)     There are six main development/maintenance pushes that need
702) attention:

703)     </p>

704) 

705)     <ul>

706) 

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

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

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

714) 

715)     <li>

716)     User support: With this many users, a lot of people are asking
717) questions
718)     all the time, offering to help out with things, and so on. We need
719) good
720)     clean docs, and we need to spend some effort coordinating
721) volunteers.

722)     </li>

723) 

724)     <li>

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

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

728)     reminders to upgrade, and so on. The network itself is a commons,
729) and
730)     somebody needs to spend some energy making sure the relay operators
731) stay
732)     happy. We also need to work on stability on some platforms —
733) e.g.,

734)     Tor relays have problems on Win XP currently.

735)     </li>

736) 

737)     <li>

738)     Usability: Beyond documentation, we also need to work on usability
739) of the
740)     software itself. This includes installers, clean GUIs, easy
741) configuration
742)     to interface with other applications, and generally automating all
743) of

744)     the difficult and confusing steps inside Tor.
745)     Usability for privacy software has never been easy.

746)     </li>

747) 

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

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

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

755) 

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

761)     critical <a href="<page getinvolved/volunteer>#Research">Tor
762) research questions</a>
763)     that will help us figure out how to make Tor secure against the
764) variety of
765)     attacks out there. Of course, there are more research questions
766) waiting

767)     behind these.
768)     </li>

769) 

770)     </ul>

771) 

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

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

776)     can keep up</a>.

777)     Now would be an excellent time to add a few more developers to the
778) effort

779)     so we can continue to grow the network.
780)     </p>

781) 

782)     <p>
783)     We are also excited about tackling related problems, such as
784)     censorship-resistance.
785)     </p>

786) 

787)     <p>

788)     We are proud to have <a href="<page about/sponsors>">sponsorship and
789) support</a>
790)     from the Omidyar Network, the International Broadcasting Bureau,
791) Bell
792)     Security Solutions, the Electronic Frontier Foundation, several
793) government

794)     agencies and research groups, and hundreds of private contributors.
795)     </p>

796) 

797)     <p>

798)     However, this support is not enough to keep Tor abreast of changes
799) in the
800)     Internet privacy landscape. Please <a href="<page
801) donate/donate>">donate</a>
802)     to the project, or <a href="<page about/contact>">contact</a> our
803) executive

804)     director for information on making grants or major donations.
805)     </p>

806) 

807)     <hr>
808) 
809) 
810)     <a id="Mobile"></a>

811)     <h3><a class="anchor" href="#Mobile">Can I use Tor on my phone or mobile

812)     device?</a></h3>
813) 
814)     <p>

815)     Tor on Android devices is maintained by the <a
816)     href="https://guardianproject.info">Guardian Project</a>. Currently, there
817)     is no supported way of using Tor on iOS; the Guardian Project is

818)     working to make this a reality in the future.
819)     </p>
820) 

821)     <hr>
822) 

823)     <a id="OutboundPorts"></a>
824)     <h3><a class="anchor" href="#OutboundPorts">Which outbound ports must be open when
825)     using Tor as a client?</a></h3>

826)     <p>

827)     Tor may attempt to connect to any port that is advertised in the
828)     directory as an ORPort (for making Tor connections) or a DirPort (for

829)     fetching updates to the directory). There are a variety of these ports:
830)     many of them are running on 80, 443, 9001, and 9030, but many use other
831)     ports too.

832)     </p>
833)     <p>

834)     When using Tor as a client, you could probably get away with opening only those four

835)     ports. Since Tor does all its connections in the background, it will retry
836)     ones that fail, and hopefully you'll never have to know that it failed, as
837)     long as it finds a working one often enough. However, to get the most

838)     diversity in your entry nodes — and thus the most security
839)     — as well as the most robustness in your connectivity, you'll
840)     want to let it connect to all of them.
841)     See the FAQ entry on <a href="#FirewallPorts">firewalled ports</a> if
842)     you want to explicitly tell your Tor client which ports are reachable
843)     for you.
844)     </p>

845) 

846)     <hr>

847) 

848)     <a id="IsItWorking"></a>

849)     <h3><a class="anchor" href="#IsItWorking">How can I tell if Tor is

850)     working, and that my connections really are anonymized?</a></h3>

851) 
852)     <p>

853)     There are sites you can visit that will tell you if you appear to be

854)     coming through the Tor network. Try the <a href="https://check.torproject.org">
855)     Tor Check</a> site and see whether it thinks you are using Tor or not.

856)     </p>

857) 

858)     <hr>

859) 

860)     <a id="FTP"></a>
861)     <h3><a class="anchor" href="#FTP">How do I use my browser for ftp with Tor?
862)     </a></h3>
863) 

864)     <p>

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

867)     ftp client, we've heard good things about  FileZilla for Windows. You can
868)     configure it to point to Tor as a "socks4a" proxy on "localhost" port
869)     "9050".

870)     </p>

871) 

872)     <hr>

873) 

874)     <a id="NoDataScrubbing"></a>

875)     <h3><a class="anchor" href="#NoDataScrubbing">Does Tor remove personal

876)     information from the data my application sends?</a></h3>
877) 

878)     <p>No, it doesn't. You need to use a separate program that understands
879)     your application and protocol and knows how to clean or "scrub" the data

880)     it sends. The Tor Browser tries to keep application-level data,

881)     like the user-agent string, uniform for all users. The Tor Browser can't
882)     do anything about text that you type into forms, though. <a

883)     href="<page download/download-easy>#warning">Be

884)     careful and be smart.</a>
885)     </p>
886) 
887)     <hr>
888) 

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

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

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

892) 

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

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

896)     <hr>

897) 

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

899)     <h3><a class="anchor" href="#SSLcertfingerprint">What are the SSL

900)     certificate fingerprints for Tor's various websites?</a></h3>

901)     <p>

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

903)     </p>
904)     <pre>
905) Issued Certificate
906) Version: 3
907) Serial Number: 09 48 B1 A9 3B 25 1D 0D B1 05 10 59 E2 C2 68 0A
908) Not Valid Before: 2013-10-22
909) Not Valid After: 2016-05-03
910) Certificate Fingerprints
911) SHA1: 84 24 56 56 8E D7 90 43 47 AA 89 AB 77 7D A4 94 3B A1 A7 D5
912) MD5: A4 16 66 80 AE B9 A4 EC AA 88 01 1B 6F B9 EB CB

913)     </pre>

914) <br>
915)     <p>
916) blog.torproject.org SSL certificate from RapidSSL:

917)     </p>

918)     <pre>
919) Issued Certificate
920) Version: 3
921) Serial Number: 05 CA 2A A9 A5 D6 ED 44 C7 2D 88 1A 18 B0 E7 DC
922) Not Valid Before: 2014-04-09
923) Not Valid After: 2017-06-14
924) Certificate Fingerprints
925) SHA1: DE 20 3D 46 FD C3 68 EB BA 40 56 39 F5 FA FD F5 4E 3A 1F 83
926) MD5: 8A 8A A2 5E D9 7F 84 4C 8F 00 3B 43 E0 2D E6 4D
927)     </pre>

928)     <hr>
929) 

930)     <a id="CompilationAndInstallation"></a>
931)     <h2><a class="anchor">Compilation And Installation:</a></h2>
932) 

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

934)     <h3><a class="anchor" href="#HowUninstallTor">How do I uninstall
935) Tor?</a></h3>
936) 
937)     <p>
938)     Tor Browser does not install itself in the classic sense of
939) applications. You just simply delete the folder or directory named "Tor
940) Browser" and it is removed from your system.
941)     </p>

942) 

943)     <p>

944)     If this is not related to Tor Browser, uninstallation depends
945) entirely on how you installed it and which operating system you
946)     have. If you installed a package, then hopefully your package has a
947) way to

948)     uninstall itself. The Windows packages include uninstallers.

949)     </p>

950) 

951)     <p>
952)     For Mac OS X, follow the <a
953)     href="<page docs/tor-doc-osx>#uninstall">uninstall directions</a>.
954)     </p>

955) 

956)     <p>

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

961)     be pretty easy to notice things there.
962)     </p>

963) 

964)     <hr>

965) 

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

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

969) 

970)     <p>

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

973)     exactly the one that we intended you to get.
974)     </p>

975) 

976)     <p>
977)     Please read the <a

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

980)     </p>

981) 

982) <hr>
983) 
984) <a id="GetTor"></a>
985) <h3><a class="anchor" href="#GetTor">Your website is blocked in my
986) country. How do I download Tor?</a></h3>
987) 
988) <p>
989) Some government or corporate firewalls censor connections to Tor's
990) website. In those cases, you have three options. First, get it from

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

992) fits nicely on a USB key. Second, find the <a

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

995) for the <a href="<page getinvolved/mirrors>">Tor mirrors</a> page
996) and see if any of those copies of our website work for you. Third,

997) you can download Tor Browser via email: log in to your email account
998) and send an email to '<tt>gettor@torproject.org</tt>' with one of the
999) following words in the body of the message: <tt>windows</tt>,
1000) <tt>osx</tt> or <tt>linux</tt> (case insensitive).
1001) You will receive a reply with links from popular cloud services to

1002) download Tor Browser for Windows, Mac OS X or Linux, depending on the

1003) option you chose. Currently, the only cloud service supported is

1004) Dropbox. If you send a blank message or anything different from the
1005) options mentioned, you will receive a help message with detailed

1006) instructions to ask for Tor Browser via email. Please note that you
1007) can use this service from any email address: gmail, yahoo, hotmail,
1008) riseup, etc. The only restriction is that you can do a maximum of
1009) three requests in a row, after that you'll have to wait 20 minutes to
1010) use it again. See the <a href="../projects/gettor.html">GetTor</a>
1011) section for more information.

1012) </p>
1013) 
1014) <p>

1015) Be sure to <a href="<page docs/verifying-signatures>">verify the
1016) signature</a>

1017) of any package you download, especially when you get it from somewhere
1018) other than our official HTTPS website.

1019) </p>
1020) 

1021)     <hr>

1022) 

1023)     <a id="VirusFalsePositives"></a>

1024)     <h3><a class="anchor" href="#VirusFalsePositives">Why does my
1025)     Tor executable appear to have a virus or spyware?</a></h3>

1026)     <p>

1027)     Sometimes, overzealous Windows virus and spyware detectors trigger on
1028)     some parts of the Tor Windows binary. Our best guess is that these are
1029)     false positives — after all, the anti-virus and anti-spyware business is
1030)     just a guessing game anyway. You should contact your vendor and explain
1031)     that you have a program that seems to be triggering false positives. Or

1032)     pick a better vendor.
1033)     </p>

1034)     <p>In the meantime, we encourage you to not just take our word for it.
1035)     Our job is to provide the source; if you're concerned, please do

1036)     recompile it yourself.</p>
1037) 
1038)     <hr>
1039) 

1040)     <a id="tarballs"></a>

1041)     <h3><a class="anchor" href="#tarballs">How do I open a .tar.gz

1042)     or .tar.xz file?</a></h3>

1043) 
1044)     <p>
1045)     Tar is a common archive utility for Unix and Linux systems. If your

1046)     system has a mouse, you can usually open them by double clicking.
1047)     Otherwise open a command prompt and execute</p>

1048)     <pre>tar xzf &lt;FILENAME&gt;.tar.gz</pre> or <pre>tar xJf &lt;FILENAME&gt;.tar.xz</pre>

1049)     <p>

1050)     as documented on tar's man page.

1051)     </p>
1052) 
1053)     <hr>
1054) 

1055)     <a id="LiveCD"></a>

1056)     <h3><a class="anchor" href="#LiveCD">Is there a LiveCD or other
1057) bundle that includes Tor?</a></h3>

1058) 

1059)     <p>

1060)     Yes.  Use <a href="https://tails.boum.org/">The Amnesic Incognito

1061)     Live System</a> or <a href="<page projects/torbrowser>">Tor Browser</a>.

1062)     </p>

1063) 
1064) <hr>
1065) 

1066) <a id="TBBGeneral"></a>

1067) <h2><a class="anchor">Tor Browser (general):</a></h2>

1068) 

1069) <a id="TBBFlash"></a>

1070) <h3><a class="anchor" href="#TBBFlash">Why can't I view videos on

1071) some Flash-based sites?</a></h3>

1072) 
1073) <p>

1074) Some sites require third party browser plugins such as Flash.

1075) Plugins operate independently from Firefox and can perform
1076) activity on your computer that ruins your anonymity. This includes

1077) but is not limited to: completely disregarding
1078) proxy settings, querying your <a

1079) href="http://forums.sun.com/thread.jspa?threadID=5162138&messageID=9618376">
1080) local IP address</a>, and <a

1081) href="http://epic.org/privacy/cookies/flash.html">storing their own
1082) cookies</a>. It is possible to use a LiveCD solution such as

1083) or <a href="https://tails.boum.org/">The Amnesic Incognito Live System</a>
1084) that creates a secure, transparent proxy to protect you from proxy bypass,
1085) however issues with local IP address discovery and Flash cookies still remain.

1086) </p>

1087) 

1088) <hr>
1089) 

1090) <a id="Ubuntu"></a>
1091) <h3><a class="anchor" href="#Ubuntu">

1092) I'm using Ubuntu and I can't start Tor Browser.</a></h3>

1093) <p>

1094) You'll need to tell Ubuntu that you want the ability to execute shell scripts
1095) from the graphical interface. Open "Files" (Unity's explorer), open
1096) Preferences-> Behavior Tab -> Set "Run executable text files when they are

1097) opened" to "Ask every time", then OK.

1098) </p>
1099) <p>You can also start the Tor Browser from the command line by running </p>

1100) <pre>./start-tor-browser</pre>

1101) <p>
1102) from inside the Tor Browser directory.
1103) </p>
1104) 

1105) <hr>
1106) 

1107) <a id="SophosOnMac"></a>
1108) <h3><a class="anchor" href="#SophosOnMac">I'm using the Sophos anti-virus

1109)     software on my Mac, and Tor starts but I can't browse anywhere.</a></h3>

1110) <p>

1111) You'll need to modify Sophos anti-virus so that Tor can connect to the
1112) internet. Go to Preferences -> Web Protection -> General, and turn off

1113) the protections for "Malicious websites" and "Malicious downloads".
1114) </p>

1115) <p>

1116) We encourage affected Sophos users to contact Sophos support about

1117) this issue.
1118) </p>

1119) 

1120) <hr>
1121) 

1122) <a id="XPCOMError"></a>

1123) <h3><a class="anchor" href="#XPCOMError">When I start Tor Browser I get an 
1124) error message: "Cannot load XPCOM".</a></h3>

1125) 
1126) <p>

1127) This <a 
1128) href="https://trac.torproject.org/projects/tor/ticket/10789">problem</a> is 
1129) specifically caused by the Webroot SecureAnywhere Antivirus software. 
1130) From the Webroot control panel, go to Identity Protection &rarr; Application 
1131) Protection, and set all the files in your Tor Browser folder to 'Allow'. 
1132) We encourage affected Webroot users to contact Webroot support about this 
1133) issue.

1134) </p>

1135) 
1136) <hr>
1137) 

1138) <a id="TBBOtherExtensions"></a>
1139) <h3><a class="anchor" href="#TBBOtherExtensions">Can I install other
1140) Firefox extensions?</a></h3>
1141) 
1142) <p>

1143) The Tor Browser is free software, so there is nothing preventing you from
1144) modifying it any way you like. However, we do not recommend installing any

1145) additional Firefox add-ons with Tor Browser. Add-ons can break

1146) your anonymity in a number of ways, including browser fingerprinting and

1147) bypassing proxy settings.

1148) </p>

1149) <p>

1150) Some people have suggested we include ad-blocking software or

1151) anti-tracking software with the Tor Browser. Right now, we do not
1152) think that's such a good idea. Tor Browser aims to provide

1153) sufficient privacy that additional add-ons to stop ads and trackers are
1154) not necessary. Using add-ons like these may cause some sites to break, which

1155) <a href="https://www.torproject.org/projects/torbrowser/design/#philosophy">

1156) we don't want to do</a>. Additionally, maintaining a list of "bad" sites that
1157) should be black-listed provides another opportunity to uniquely fingerprint
1158) users.

1159) </p>

1160) 

1161) <hr>
1162) 

1163) <a id="TBBJavaScriptEnabled"></a>

1164) <a id="TBBCanIBlockJS"></a>

1165) <h3><a class="anchor" href="#TBBJavaScriptEnabled">Why is NoScript

1166) configured to allow JavaScript by default in Tor Browser?

1167) Isn't that unsafe?</a></h3>

1168) 
1169) <p>

1170) We configure NoScript to allow JavaScript by default in Tor
1171) Browser because many websites will not work with JavaScript

1172) disabled.  Most users would give up on Tor entirely if a website
1173) they want to use requires JavaScript, because they would not know
1174) how to allow a website to use JavaScript (or that enabling
1175) JavaScript might make a website work).
1176) </p>
1177) 

1178) <p>
1179) There's a tradeoff here. On the one hand, we should leave
1180) JavaScript enabled by default so websites work the way
1181) users expect. On the other hand, we should disable JavaScript
1182) by default to better protect against browser vulnerabilities (<a

1183) href="https://blog.torproject.org/blog/tor-security-advisory-old-tor-browser-bundles-vulnerable">
1184) not just a theoretical concern!</a>). But there's a third issue: websites

1185) can easily determine whether you have allowed JavaScript for them,
1186) and if you disable JavaScript by default but then allow a few websites
1187) to run scripts (the way most people use NoScript), then your choice of
1188) whitelisted websites acts as a sort of cookie that makes you recognizable
1189) (and distinguishable), thus harming your anonymity.
1190) </p>

1191) 
1192) <p>

1193) Ultimately, we want the default Tor bundles to use
1194) a combination of firewalls (like the iptables rules
1195) in <a href="https://tails.boum.org/">Tails</a>) and <a
1196) href="https://trac.torproject.org/projects/tor/ticket/7680">sandboxes</a>
1197) to make JavaScript not so scary. In
1198) the shorter term, TBB 3.0 will hopefully <a
1199) href="https://trac.torproject.org/projects/tor/ticket/9387">allow users
1200) to choose their JavaScript settings more easily</a> &mdash; but the
1201) partitioning concern will remain.

1202) </p>
1203) 
1204) <p>

1205) Until we get there, feel free to leave JavaScript on or off depending
1206) on your security, anonymity, and usability priorities.

1207) </p>
1208) 
1209) <hr>
1210) 

1211) <a id="TBBOtherBrowser"></a>
1212) <h3><a class="anchor" href="#TBBOtherBrowser">I want to use
1213) Chrome/IE/Opera/etc with Tor.</a></h3>
1214) 
1215) <p>

1216) In short, using any browser besides Tor Browser with Tor is a

1217) really bad idea.
1218) </p>
1219) 
1220) <p>

1221) Our efforts to work with the Chrome team to <a
1222) href="https://blog.torproject.org/blog/google-chrome-incognito-mode-tor-and-fingerprinting">add
1223) missing APIs</a> were unsuccessful, unfortunately. Currently, it is impossible
1224) to use other browsers and get the same level of protections as when using the
1225) Tor Browser.

1226) </p>
1227) 
1228) <hr>
1229) 

1230) <a id="GoogleCAPTCHA"></a>
1231) <h3><a class="anchor" href="#GoogleCAPTCHA">Google makes me solve a
1232) CAPTCHA or tells me I have spyware installed.</a></h3>

1233) 
1234) <p>
1235) This is a known and intermittent problem; it does not mean that Google
1236) considers Tor to be spyware.
1237) </p>
1238) 
1239) <p>

1240) When you use Tor, you are sending queries through exit relays that are

1241) also shared by thousands of other users. Tor users typically see this
1242) message when many Tor users are querying Google in a short period of time.
1243) Google interprets the high volume of traffic from a single IP address
1244) (the exit relay you happened to pick) as somebody trying to "crawl" their
1245) website, so it slows down traffic from that IP address for a short time.

1246) </p>
1247) <p>
1248) An alternate explanation is that Google tries to detect certain
1249) kinds of spyware or viruses that send distinctive queries to Google
1250) Search. It notes the IP addresses from which those queries are received
1251) (not realizing that they are Tor exit relays), and tries to warn any
1252) connections coming from those IP addresses that recent queries indicate
1253) an infection.
1254) </p>
1255) 
1256) <p>

1257) To our knowledge, Google is not doing anything intentionally specifically

1258) to deter or block Tor use. The error message about an infected machine
1259) should clear up again after a short time.
1260) </p>
1261) 
1262) <hr />
1263) 

1264) <a id="ForeignLanguages"></a>
1265) <h3><a class="anchor" href="#ForeignLanguages">
1266) Why does Google show up in foreign languages?</a></h3>
1267) 
1268) <p>

1269)  Google uses "geolocation" to determine where in the world you are, so it
1270)  can give you a personalized experience. This includes using the language
1271)  it thinks you prefer, and it also includes giving you different results

1272)  on your queries.

1273) </p>
1274) <p>

1275) If you really want to see Google in English you can click the link that
1276) provides that. But we consider this a feature with Tor, not a bug --- the
1277) Internet is not flat, and it in fact does look different depending on

1278) where you are. This feature reminds people of this fact.

1279) </p>
1280) <p>

1281) Note that Google search URLs take name/value pairs as arguments and one
1282) of those names is "hl". If you set "hl" to "en" then Google will return
1283) search results in English regardless of what Google server you have been
1284) sent to. On a query this looks like:

1285) </p>

1286) <pre>https://encrypted.google.com/search?q=online%20anonymity&hl=en</pre>

1287) <p>

1288) Another method is to simply use your country code for accessing Google.
1289) This can be google.be, google.de, google.us and so on.

1290) </p>
1291) <hr />

1292) <a id="GmailWarning"></a>

1293) <h3><a class="anchor" href="#GmailWarning">Gmail warns me that my

1294) account may have been compromised.</a></h3>

1295) 
1296) <p>
1297) Sometimes, after you've used Gmail over Tor, Google presents a
1298) pop-up notification that your account may have been compromised.
1299) The notification window lists a series of IP addresses and locations
1300) throughout the world recently used to access your account.
1301) </p>
1302) 
1303) <p>
1304) In general this is a false alarm: Google saw a bunch of logins from

1305) different places, as a result of running the service via Tor, and
1306) decided

1307) it was a good idea to confirm the account was being accessed by it's
1308) rightful owner.
1309) </p>
1310) 
1311) <p>
1312) Even though this may be a biproduct of using the service via tor,
1313) that doesn't mean you can entirely ignore the warning. It is
1314) <i>probably</i> a false positive, but it might not be since it is
1315) possible for someone to hijack your Google cookie.
1316) </p>
1317) 
1318) <p>
1319) Cookie hijacking is possible by either physical access to your computer
1320) or by watching your network traffic.  In theory only physical access
1321) should compromise your system because Gmail and similar services
1322) should only send the cookie over an SSL link. In practice, alas, it's <a

1323) href="http://fscked.org/blog/fully-automated-active-https-cookie-
1324) hijacking">

1325) way more complex than that</a>.
1326) </p>
1327) 
1328) <p>
1329) And if somebody <i>did</i> steal your google cookie, they might end
1330) up logging in from unusual places (though of course they also might
1331) not). So the summary is that since you're using Tor, this security
1332) measure that Google uses isn't so useful for you, because it's full of
1333) false positives. You'll have to use other approaches, like seeing if
1334) anything looks weird on the account, or looking at the timestamps for
1335) recent logins and wondering if you actually logged in at those times.
1336) </p>
1337) 
1338) <hr>
1339) 

1340) <a id="NeedToUseAProxy"></a>

1341) <h3><a class="anchor" href="#NeedToUseAProxy">My internet connection

1342) requires an HTTP or SOCKS Proxy</a></h3>

1343) 
1344) <p>

1345) You can set Proxy IP address, port, and authentication information in
1346) Tor Browser's Network Settings. If you're using Tor another way, check
1347) out the HTTPProxy and HTTPSProxy config options in the <a

1348) href="<page docs/tor-manual>">man page</a>,

1349) and modify your torrc file accordingly. You will need an HTTP proxy for
1350) doing GET requests to fetch the Tor directory, and you will need an
1351) HTTPS proxy for doing CONNECT requests to get to Tor relays. (It's fine
1352) if they're the same proxy.) Tor also recognizes the torrc options
1353) Socks4Proxy and Socks5Proxy.

1354) </p>
1355) <p>

1356) Also read up on the HTTPProxyAuthenticator and HTTPSProxyAuthenticator
1357) options if your proxy requires auth. We only support basic auth currently,
1358) but if you need NTLM authentication, you may find <a
1359) href="http://archives.seul.org/or/talk/Jun-2005/msg00223.html">this post
1360) in the archives</a> useful.

1361) </p>
1362) <p>

1363) If your proxies only allow you to connect to certain ports, look at the
1364) entry on <a href="#FirewallPorts">Firewalled clients</a> for how
1365) to restrict what ports your Tor will try to access.

1366) </p>
1367) 
1368) <hr>
1369) 

1370) 
1371) <a id="TBBSocksPort"></a>
1372) <h3><a class="anchor" href="#TBBSocksPort">
1373) I want to run another application through Tor.</a></h3>
1374) 
1375) <p>
1376) If you are trying to use some external application with Tor, step zero
1377) should be to <a href="<page download/download>#warning">reread the set
1378) of warnings</a> for ways you can screw up. Step one should be to try
1379) to use a SOCKS proxy rather than an HTTP proxy.
1380) Typically Tor listens for SOCKS connections on port 9050. Tor Browser listens
1381) on port 9150.
1382) </p>
1383) 
1384) <p>
1385) If your application doesn't support SOCKS proxies, feel free to install <a
1386) href="http://www.privoxy.org/">privoxy</a>.
1387) However, please realize that this approach is not recommended for novice
1388) users. Privoxy has an <a
1389) href="http://www.privoxy.org/faq/misc.html#TOR">example
1390) configuration</a> of Tor and Privoxy.
1391) </p>
1392) 
1393) <p>

1394) If you're unable to use the application's native proxy settings, all hope is

1395) not lost. See <a href="#CantSetProxy">below</a>.
1396) </p>
1397) 
1398) <hr>
1399) 

1400) <a id="CantSetProxy"></a>

1401) <h3><a class="anchor" href="#CantSetProxy">What should I do if I can't

1402) set a proxy with my application?</a></h3>
1403) 
1404) <p>

1405) On Unix, we recommend you give <a
1406) href="https://github.com/dgoulet/torsocks/">torsocks</a> a try.
1407) Alternative proxifying tools like <a
1408) href="http://www.dest-unreach.org/socat/">socat</a> and <a
1409) href="http://proxychains.sourceforge.net/">proxychains</a> are also

1410) available.</p>

1411) <p>
1412) The Windows way to force applications through Tor is less clear. <a
1413) href="http://freecap.ru/eng/">Some</a> <a
1414) href="http://www.freehaven.net/~aphex/torcap/">tools</a> have been <a

1415) href="http://www.crowdstrike.com/community-tools/index.html#tool-79">proposed

1416) </a>, but we'd also like to see further testing done here.

1417) </p>
1418) 
1419) <hr>
1420) 

1421) <a id="TBB3.x"></a>

1422) <h2><a class="anchor">Tor Browser (3.x and later):</a></h2>

1423)     <a id="WhereDidVidaliaGo"></a>

1424)     <h3><a class="anchor" href="#WhereDidVidaliaGo">Where did the world map

1425)     (Vidalia) go?</a></h3>
1426) 

1427)     <p>Vidalia has been replaced with Tor Launcher, which is a Firefox
1428)     extension that provides similar functionality. Unfortunately, circuit
1429)     status reporting is still missing, but we are <a
1430)     href="https://trac.torproject.org/projects/tor/ticket/8641">working

1431)     on providing it</a>. </p>
1432) 
1433)     <hr>
1434) 
1435)     <a id="DisableJS"></a>
1436)     <h3><a class="anchor" href="#DisableJS">How do I disable JavaScript?</a>
1437)     </h3>
1438) 

1439)     <p>Alas, Mozilla decided to get rid of the config checkbox for JavaScript
1440)     from earlier Firefox versions. And since TBB 3.5 is based on Firefox 24
1441)     (FF17 is unmaintained), that means TBB 3.5 doesn't have the config

1442)     checkbox anymore either, which is unfortunate.</p>
1443) 

1444)     <p>The simplest way to disable JavaScript in TBB 3.5 is to click on the
1445)     Noscript "S" (between the green onion and the address bar), and select
1446)     "Forbid scripts globally". Note that vanilla NoScript actually whitelists
1447)     several domains even when you try to disable scripts globally, whereas

1448)     Tor Browser's NoScript configuration disables all of them. </p>
1449) 

1450)     <p>The more klunky way to disable JavaScript is to go to about:config,

1451)     find javascript.enabled, and set it to false.</p>
1452) 
1453)     <p>There is also a very simple addon available at addons.mozilla.org
1454)     called QuickJS, which provides a toolbar toggle for the javascript.enabled

1455)     about:config control. There are no configuration options for the addon,
1456)     it just switches the javascript.enabled entry between true and false and

1457)     provides a button for it. </p>
1458) 

1459)     <p>If you want to be extra safe, use both the about:config setting and

1460)     NoScript. </p>
1461) 

1462)     <p>As for whether you should disable it or leave it enabled, that's <a

1463)     href="#TBBJavaScriptEnabled">a tradeoff we leave to you</a>.</p>

1464) 
1465)     <hr>
1466) 
1467)     <a id="VerifyDownload"></a>
1468)     <h3><a class="anchor" href="#VerifyDownload">How do I verify the download
1469)     (sha256sums.txt)?</a></h3>
1470) 

1471)     <p>Instructions are on the <a
1472)     href="<page docs/verifying-signatures>#BuildVerification">verifying

1473)     signatures</a> page.</p>

1474) 
1475)     <hr>

1476) 

1477)     <a id="NewIdentityClosingTabs"></a>

1478)     <h3><a class="anchor" href="#NewIdentityClosingTabs">Why does "New

1479)     Identity" close all my open tabs?</a></h3>
1480) 
1481)     <p>

1482)     That's actually a feature, since it's discarding your application-level

1483)     browser data too.

1484)     </p>
1485) 
1486)     <p>

1487)     We're working on ways to make the behavior less surprising, e.g. a popup
1488)     warning or auto restoring tabs. See ticket <a
1489)     href="https://trac.torproject.org/projects/tor/ticket/9906">#9906</a> and
1490)     ticket <a
1491)     href="https://trac.torproject.org/projects/tor/ticket/10400">#10400</a>
1492)     to follow progress there.

1493)     </p>
1494) 
1495)     <hr>
1496) 
1497)     <a id="ConfigureRelayOrBridge"></a>
1498)     <h3><a class="anchor" href="#ConfigureRelayOrBridge">How do I configure Tor as a relay or bridge?</a></h3>
1499) 
1500)     <p>

1501)     You've got three options.

1502)     </p>
1503) 
1504)     <p>

1505)     First (best option), if you're on Linux, you can install the system
1506)     Tor package (e.g. apt-get install tor) and then set it up to be a relay
1507)     (<a href="https://www.torproject.org/docs/tor-relay-debian">instructions</a>).

1508)     You can then use TBB independent of that.
1509)     </p>
1510) 
1511) 
1512)     <p>

1513)     Second (complex option), you can edit your torrc file (in Data/Tor/torrc)

1514)     directly to add the following lines:

1515)     </p>
1516)     <pre>
1517)     ORPort 443
1518)     Exitpolicy reject *:*
1519)     BridgeRelay 1  # only add this line if you want to be a bridge
1520)     </pre>
1521)     <p>

1522)     If you've installed <a

1523)     href="<page projects/obfsproxy-debian-instructions>#instructions">Obfsproxy</a>,

1524)     you'll need to add one more line:
1525)     </p>
1526)     <pre>
1527)     ServerTransportPlugin obfs3 exec /usr/bin/obfsproxy managed
1528)     </pre>
1529) 
1530)     <hr>
1531) 
1532)     <a id="Timestamps"></a>

1533)     <h3><a class="anchor" href="#Timestamps">Why are the file timestamps

1534)     from 2000?</a></h3>
1535) 

1536)     <p>One of the huge new features in TBB 3.x is the "deterministic build"

1537)     process, which allows many people to build Tor Browser and

1538)     verify that they all make exactly the same package. See Mike's <a
1539)     href="https://blog.torproject.org/blog/deterministic-builds-part-one-cyberwar-and-global-compromise">first
1540)     blog</a> post for the motivation, and his <a

1541)     href="https://blog.torproject.org/blog/deterministic-builds-part-two-technical-details">second

1542)     blog post</a> for the technical details of how we do it.

1543)     </p>
1544) 

1545)     <p>Part of creating identical builds is having everybody use the same
1546)     timestamp. Mike picked the beginning of 2000 for that time. The reason

1547)     you might see 7pm in 1999 is because of time zones. </p>
1548) 
1549)     <hr>
1550) 

1551)     <a id="TBBSourceCode"></a>

1552)     <h3><a class="anchor" href="#TBBSourceCode">Where is the source code for

1553)     Tor Browser? How do I verify a build?</a></h3>

1554) 
1555)     <p>

1556)     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/tree/gitian/README.build">https://gitweb.torproject.org/builders/tor-browser-bundle.git/tree/gitian/README.build</a>.

1557)     </p>
1558) 
1559) 

1560) <hr>
1561) 

1562) <a id="AdvancedTorUsage"></a>
1563) <h2><a class="anchor">Advanced Tor usage:</a></h2>
1564) 

1565) <a id="torrc"></a>

1566) <h3><a class="anchor" href="#torrc">I'm supposed to "edit my torrc".
1567) What does that mean?</a></h3>

1568) 
1569) <p>
1570) Tor installs a text file called torrc that contains configuration
1571) instructions for how your Tor program should behave. The default

1572) configuration should work fine for most Tor users.

1573) </p>

1574) <p>

1575) If you installed Tor Browser, look for

1576) <code>Browser/TorBrowser/Data/Tor/torrc</code> inside your Tor Browser
1577) directory.

1578) On OS X, you must right-click or command-click on the Tor Browser icon,

1579) and select "Show Package Contents" before the Tor Browser directories become
1580) visible.

1581) </p>
1582) <p>

1583) 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>

1584) 
1585) <p>

1586) Once you've changed your torrc, you will need to restart tor for the
1587) changes to take effect. (For advanced users, note that

1588) you actually only need to send Tor a HUP signal, not actually restart
1589) it.)

1590) </p>
1591) 
1592) <p>

1593) For other configuration options you can use, see the <a href="<page

1594) docs/tor-manual>">Tor manual page</a>. Have a look at <a

1595) href="https://gitweb.torproject.org/tor.git/tree/src/config/torrc.sample.in">

1596) the sample torrc file</a> for hints on common configurations. Remember, all
1597) lines beginning with # in torrc are treated as comments and have no effect

1598) on Tor's configuration.

1599) </p>
1600) 
1601) <hr>
1602) 

1603) <a id="Logs"></a>

1604) <h3><a class="anchor" href="#Logs">How do I set up logging, or see Tor's
1605) logs?</a></h3>

1606) 
1607) <p>

1608) You'll have to go find the log files by

1609) hand. Here are some likely places for your logs to be:

1610) </p>
1611) 
1612) <ul>
1613) <li>On OS X, Debian, Red Hat, etc, the logs are in /var/log/tor/
1614) </li>

1615) <li>On Windows, there are no default log files currently. If you enable
1616) logs in your torrc file, they default to <code>\username\Application
1617) Data\tor\log\</code> or <code>\Application Data\tor\log\</code>
1618) </li>
1619) <li>If you compiled Tor from source, by default your Tor logs to <a
1620) href="http://en.wikipedia.org/wiki/Standard_streams">"stdout"</a>
1621) at log-level notice. If you enable logs in your torrc file, they
1622) default to <code>/usr/local/var/log/tor/</code>.

1623) </li>
1624) </ul>
1625) 
1626) <p>

1627) To change your logging setup by hand, <a href="#torrc">edit your
1628) torrc</a>

1629) and find the section (near the top of the file) which contains the
1630) following line:

1631) </p>
1632) 
1633) <pre>

1634) \## Logs go to stdout at level "notice" unless redirected by something
1635) \## else, like one of the below lines.

1636) </pre>

1637) 
1638) <p>

1639) For example, if you want Tor to send complete debug, info, notice, warn,

1640) and err level messages to a file, append the following line to the end
1641) of the section:
1642) </p>
1643) 
1644) <pre>
1645) Log debug file c:/program files/tor/debug.log
1646) </pre>
1647) 
1648) <p>

1649) Replace <code>c:/program files/tor/debug.log</code> with a directory
1650) and filename for your Tor log.

1651) </p>
1652) 
1653) <hr>
1654) 

1655) 
1656) <a id="LogLevel"></a>
1657) <h3><a class="anchor" href="#LogLevel">What log level should I use?</a></h3>
1658) 
1659) <p>

1660) There are five log levels (also called "log severities") you might see in

1661) Tor's logs:

1662) </p>
1663) 
1664) <ul>

1665)     <li>"err": something bad just happened, and we can't recover. Tor will

1666)     exit.</li>

1667)     <li>"warn": something bad happened, but we're still running. The bad
1668)     thing might be a bug in the code, some other Tor process doing something
1669)     unexpected, etc. The operator should examine the message and try to

1670)     correct the problem.</li>

1671)     <li>"notice": something the operator will want to know about.</li>

1672)     <li>"info": something happened (maybe bad, maybe ok), but there's

1673)     nothing you need to (or can) do about it.</li>

1674)     <li>"debug": for everything louder than info. It is quite loud indeed.</li>

1675) </ul>
1676) 
1677) <p>

1678) Alas, some of the warn messages are hard for ordinary users to correct -- the
1679) developers are slowly making progress at making Tor automatically react

1680) correctly for each situation.

1681) </p>
1682) 
1683) <p>

1684) We recommend running at the default, which is "notice". You will hear about

1685) important things, and you won't hear about unimportant things.

1686) </p>
1687) 
1688) <p>

1689) Tor relays in particular should avoid logging at info or debug in normal
1690) operation, since they might end up recording sensitive information in
1691) their logs.

1692) </p>
1693) 

1694) <hr>
1695) 

1696) <a id="DoesntWork"></a>

1697) <h3><a class="anchor" href="#DoesntWork">I installed Tor but it's not
1698) working.</a></h3>

1699) 
1700) <p>

1701) Once you've got Tor Browser up and running, the first question to

1702) ask is whether your Tor client is able to establish a circuit.

1703) </p>
1704) 

1705) <p>If Tor can establish a circuit, Tor Browser will
1706) automatically launch the browser for you. You can also check in the
1707) <a href="#Logs">Tor logs</a> for

1708) a line saying that Tor "has successfully opened a circuit. Looks like
1709) client functionality is working."
1710) </p>
1711) 
1712) <p>
1713) If Tor can't establish a circuit, here are some hints:
1714) </p>
1715) 
1716) <ol>
1717) <li>Check your system clock. If it's more than a few hours off, Tor will

1718) refuse to build circuits. For Microsoft Windows users, synchronize your
1719) clock under the clock -> Internet time tab. In addition, correct the

1720) day and date under the 'Date & Time' Tab. Also make sure your time
1721) zone is correct.</li>

1722) <li>Is your Internet connection <a href="#FirewallPorts">firewalled
1723) by port</a>, or do you normally need to use a <a

1724) href="<#NeedToUseAProxy">proxy</a>?

1725) </li>

1726) <li>Are you running programs like Norton Internet Security or SELinux
1727) that

1728) block certain connections, even though you don't realize they do? They
1729) could be preventing Tor from making network connections.</li>
1730) <li>Are you in China, or behind a restrictive corporate network firewall
1731) that blocks the public Tor relays? If so, you should learn about <a

1732) href="<page docs/bridges>">Tor bridges</a>.</li>

1733) <li>Check your <a href="#Logs">Tor logs</a>. Do they give you any hints
1734) about what's going wrong?</li>

1735) </ol>
1736) 
1737) <hr />
1738) 

1739) <a id="TorCrash"></a>
1740) <h3><a class="anchor" href="#TorCrash">My Tor keeps crashing.</a></h3>
1741) <p>

1742)  We want to hear from you! There are supposed to be zero crash bugs in Tor.
1743)  This FAQ entry describes the best way for you to be helpful to us. But even
1744)  if you can't work out all the details, we still want to hear about it, so
1745)  we can help you track it down.

1746) </p>
1747) <p>

1748) First, make sure you're using the latest version of Tor (either the latest
1749) stable or the latest development version).

1750) </p>
1751) <p>

1752) Second, make sure your version of libevent is new enough. We recommend at
1753) least libevent 1.3a.

1754) </p>
1755) <p>

1756) Third, see if there's already an entry for your bug in the <a
1757) href="https://bugs.torproject.org/">Tor bugtracker</a>. If so,
1758) check if there are any new details that you can add.

1759) </p>
1760) <p>

1761) Fourth, is the crash repeatable? Can you cause the crash? Can
1762) you isolate some of the circumstances or config options that
1763) make it happen? How quickly or often does the bug show up?
1764) Can you check if it happens with other versions of Tor, for
1765) example the latest stable release?

1766) </p>
1767) <p>

1768) Fifth, what sort of crash do you get?

1769) </p>
1770) <ul>
1771) <li>

1772) Does your Tor log include an "assert failure"? If so, please
1773) tell us that line, since it helps us figure out what's going on.
1774) Tell us the previous couple of log messages as well, especially
1775) if they seem important.

1776) </li>
1777) <li>

1778) If it says "Segmentation fault - core dumped" then you need to
1779) do a bit more to track it down. Look for a file like "core" or
1780) "tor.core" or "core.12345" in your current directory, or in your
1781) Data Directory. If it's there, run "gdb tor core" and then "bt",
1782) and include the output. If you can't find a core, run "ulimit -c
1783) unlimited", restart Tor, and try to make it crash again. (This core
1784) thing will only work on Unix -- alas, tracking down bugs on Windows
1785) is harder. If you're on Windows, can you get somebody to duplicate

1786) your bug on Unix?)
1787) </li>
1788) <li>

1789) If Tor simply vanishes mysteriously, it probably is a segmentation
1790) fault but you're running Tor in the background (as a daemon) so you
1791) won't notice. Go look at the end of your log file, and look for a
1792) core file as above. If you don't find any good hints, you should
1793) consider running Tor in the foreground (from a shell) so you can
1794) see how it dies. Warning: if you switch to running Tor in the foreground,
1795) you might start using a different torrc file, with a different default
1796) Data Directory; see the <a href="#UpgradeOrMove">relay-upgrade FAQ entry</a>
1797) for details.

1798) </li>
1799) <li>

1800) If it's still vanishing mysteriously, perhaps something else is killing it?
1801) Do you have resource limits (ulimits) configured that kill off processes
1802) sometimes? (This is especially common on OpenBSD.) On Linux, try running
1803) "dmesg" to see if the out-of-memory killer removed your process. (Tor will
1804) exit cleanly if it notices that it's run out of memory, but in some cases
1805) it might not have time to notice.) In very rare circumstances, hardware
1806) problems could also be the culprit.

1807) </li>
1808) </ul>
1809) <p>

1810) Sixth, if the above ideas don't point out the bug, consider increasing your
1811) log level to "loglevel debug". You can look at the log-configuration FAQ
1812) entry for instructions on what to put in your torrc file. If it usually
1813) takes a long time for the crash to show up, you will want to reserve a whole
1814) lot of disk space for the debug log. Alternatively, you could just send
1815) debug-level logs to the screen (it's called "stdout" in the torrc), and then
1816) when it crashes you'll see the last couple of log lines it had printed.
1817) (Note that running with verbose logging like this will slow Tor down
1818) considerably, and note also that it's generally not a good idea security-wise
1819) to keep logs like this sitting around.)

1820) </p>
1821) 
1822) <hr />
1823) 

1824)     <a id="ChooseEntryExit"></a>

1825)     <h3><a class="anchor" href="#ChooseEntryExit">Can I control which
1826) nodes (or country) are used for entry/exit?</a></h3>

1827) 

1828)     <p>

1829)     Yes. You can set preferred entry and exit nodes as well as
1830)     inform Tor which nodes you do not want to use.

1831)     The following options can be added to your config file <a
1832)     href="#torrc">"torrc"</a> or specified on the command line:

1833)     </p>
1834)     <dl>
1835)       <dt><tt>EntryNodes $fingerprint,$fingerprint,...</tt></dt>

1836)         <dd>A list of preferred nodes to use for the first hop in the
1837) circuit, if possible.

1838)         </dd>
1839)       <dt><tt>ExitNodes $fingerprint,$fingerprint,...</tt></dt>

1840)         <dd>A list of preferred nodes to use for the last hop in the
1841) circuit, if possible.

1842)         </dd>
1843)       <dt><tt>ExcludeNodes $fingerprint,$fingerprint,...</tt></dt>

1844)         <dd>A list of nodes to never use when building a circuit.

1845)         </dd>
1846)       <dt><tt>ExcludeExitNodes $fingerprint,$fingerprint,...</tt></dt>

1847)         <dd>A list of nodes to never use when picking an exit.

1848)             Nodes listed in <tt>ExcludeNodes</tt> are automatically in
1849) this list.

1850)         </dd>
1851)     </dl>
1852)     <p>

1853)     <em>We recommend you do not use these</em>

1854)     — they are intended for testing and may disappear in future
1855) versions.

1856)     You get the best security that Tor can provide when you leave the
1857)     route selection to Tor; overriding the entry / exit nodes can mess
1858)     up your anonymity in ways we don't understand.

1859)     </p>
1860)     <p>

1861)     Note also that not every circuit is used to deliver traffic outside of
1862)     the Tor network. It is normal to see non-exit circuits (such as those
1863)     used to connect to hidden services, those that do directory fetches,
1864)     those used for relay reachability self-tests, and so on) that end at
1865)     a non-exit node. To keep a node from being used entirely, see
1866)     <tt>ExcludeNodes</tt> and <tt>StrictNodes</tt> in the

1867)     <a href="<page docs/tor-manual>">manual</a>.

1868)     </p>
1869)     <p>

1870)     Instead of <tt>$fingerprint</tt> you can also specify a <a

1871) 
1872) href="https://secure.wikimedia.org/wikipedia/en/wiki/ISO_3166-1_alpha-2"
1873) >2

1874)     letter ISO3166 country code</a> in curly braces (for example <tt>{de}</tt>),

1875)     or an ip address pattern (for example 255.254.0.0/8).
1876)     Make sure there are no spaces between the commas and the

1877)     list items.

1878)     </p>
1879)     <p>

1880)     If you want to access a service directly through Tor's Socks
1881) interface

1882)     (eg. using ssh via connect.c), another option is to set up an

1883)     internal mapping in your configuration file using
1884) <tt>MapAddress</tt>.

1885)     See the manual page for details.
1886)     </p>

1887) 

1888)     <hr>

1889) 

1890) <a id="FirewallPorts"></a>

1891) <h3><a class="anchor" href="#FirewallPorts">My firewall only allows a
1892) few outgoing ports.</a></h3>

1893) 
1894) <p>
1895) If your firewall works by blocking ports, then you can tell Tor to only

1896) use the ports when you start your Tor Browser. Or you can add the ports
1897) that your firewall permits by adding "FascistFirewall 1"

1898) to

1899) your <a href="<page docs/faq>#torrc">torrc

1900) configuration file</a>.

1901) By default, when you set this Tor assumes that your firewall allows only
1902) port 80 and port 443 (HTTP and HTTPS respectively). You can select a
1903) different set of ports with the FirewallPorts torrc option.
1904) </p>
1905) 
1906) <p>
1907) If you want to be more fine-grained with your controls, you can also
1908) use the ReachableAddresses config options, e.g.:
1909) </p>
1910) 
1911) <pre>
1912)   ReachableDirAddresses *:80
1913)   ReachableORAddresses *:443
1914) </pre>
1915) 
1916) <hr>

1917) 

1918)     <a id="DefaultExitPorts"></a>

1919)     <h3><a class="anchor" href="#DefaultExitPorts">Is there a list of default exit

1920)     ports?</a></h3>

1921)     <p>

1922) The default open ports are listed below but keep in mind that, any port or
1923) ports can be opened by the relay operator by configuring it in torrc or
1924) modifying the source code. But the default according to src/or/policies.c
1925) from the source code release tor-0.2.4.16-rc is:

1926)     </p>
1927)     <pre>
1928)   reject 0.0.0.0/8
1929)   reject 169.254.0.0/16
1930)   reject 127.0.0.0/8
1931)   reject 192.168.0.0/16
1932)   reject 10.0.0.0/8
1933)   reject 172.16.0.0/12
1934)   reject *:25
1935)   reject *:119
1936)   reject *:135-139
1937)   reject *:445
1938)   reject *:563
1939)   reject *:1214
1940)   reject *:4661-4666
1941)   reject *:6346-6429
1942)   reject *:6699
1943)   reject *:6881-6999
1944)   accept *:*
1945)     </pre>
1946)     <p>

1947)     A relay will block access to its own IP address, as well local network
1948)     IP addresses. A relay always blocks itself by default. This prevents
1949)     Tor users from accidentally accessing any of the exit operator's local
1950)     services.

1951)     </p>
1952) 
1953)     <hr>
1954) 

1955)     <a id="WarningsAboutSOCKSandDNSInformationLeaks"></a>

1956)     <h3><a class="anchor" href="#WarningsAboutSOCKSandDNSInformationLeaks">I
1957)     keep seeing these warnings about SOCKS and DNS information leaks.

1958)     Should I worry?</a></h3>
1959)     <p>

1960)     The warning is:

1961)     </p>
1962)     <p>

1963)     Your application (using socks5 on port %d) is giving Tor only an IP
1964)     address. Applications that do DNS resolves themselves may leak
1965)     information. Consider using Socks4A (e.g. via Polipo or socat) instead.

1966)     </p>
1967)     <p>

1968)     If you are running Tor to get anonymity, and you are worried about an
1969)     attacker who is even slightly clever, then yes, you should worry. Here's why.

1970)     </p>
1971)     <p>

1972)     <b>The Problem.</b> When your applications connect to servers on the
1973)     Internet, they need to resolve hostnames that you can read (like
1974)     www.torproject.org) into IP addresses that the Internet can use (like
1975)     209.237.230.66). To do this, your application sends a request to a DNS
1976)     server, telling it the hostname it wants to resolve. The DNS server
1977)     replies by telling your application the IP address.

1978)     </p>
1979)     <p>

1980)     Clearly, this is a bad idea if you plan to connect to the remote host
1981)     anonymously: when your application sends the request to the DNS server,
1982)     the DNS server (and anybody else who might be watching) can see what
1983)     hostname you are asking for. Even if your application then uses Tor to
1984)     connect to the IP anonymously, it will be pretty obvious that the user
1985)     making the anonymous connection is probably the same person who made
1986)     the DNS request.

1987)     </p>
1988)     <p>

1989)     <b>Where SOCKS comes in.</b> Your application uses the SOCKS protocol
1990)     to connect to your local Tor client. There are 3 versions of SOCKS you
1991)     are likely to run into: SOCKS 4 (which only uses IP addresses), SOCKS 5
1992)     (which usually uses IP addresses in practice), and SOCKS 4a (which uses
1993)     hostnames).

1994)     </p>
1995)     <p>

1996)     When your application uses SOCKS 4 or SOCKS 5 to give Tor an IP address,
1997)     Tor guesses that it 'probably' got the IP address non-anonymously from a
1998)     DNS server. That's why it gives you a warning message: you probably aren't
1999)     as anonymous as you think.

2000)     </p>
2001)     <p>

2002)     <b>So what can I do?</b> We describe a few solutions below.

2003)     </p>
2004)     <ul>
2005)     <li>If your application speaks SOCKS 4a, use it. </li>