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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><a href="#General">General questions:</a><br />
18)     <a href="#CompilationAndInstallation">Compilation and Installation:</a><br />
19)     <a href="#TBBGeneral">Tor Browser Bundle (general):</a><br />

20)     <a href="#TBB3.x">Tor Browser Bundle (3.x series):</a><br />

21)     <a href="#AdvancedTorUsage">Advanced Tor usage:</a><br />
22)     <a href="#RunningATorRelay">Running a Tor relay:</a><br />
23)     <a href="#TorHiddenServices">Tor hidden services:</a><br />
24)     <a href="#Development">Development:</a><br />
25)     <a href="#AnonymityAndSecurity">Anonymity and Security:</a><br />
26)     <a href="#AlternateDesigns">Alternate designs that we don't do (yet):</a><br />
27)     <a href="#Abuse">Abuse:</a></p>

28) 

29) <hr>
30) 
31)     <p>General questions:</p>

32)     <ul>
33)     <li><a href="#WhatIsTor">What is Tor?</a></li>

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

36)     <li><a href="#CompatibleApplications">What programs can I use with
37)     Tor?</a></li>
38)     <li><a href="#WhyCalledTor">Why is it called Tor?</a></li>
39)     <li><a href="#Backdoor">Is there a backdoor in Tor?</a></li>

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

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

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

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

44)     <li><a href="#FileSharing">How can I share files anonymously through Tor?
45)     </a></li>

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

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

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

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

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

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

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

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

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

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

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

60)     </ul>

61) 

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

63) 

64)     <ul>
65)     <li><a href="#HowUninstallTor">How do I uninstall Tor?</a></li>
66)     <li><a href="#PGPSigs">What are these "sig" files on the download
67)     page?</a></li>

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

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

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

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

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

75)     </ul>

76) 

77)     <p>Tor Browser Bundle (general):</p>

78)     <ul>

79) 

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

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

83)     </a></li>

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

107)     </ul>
108) 

109)     <p>Tor Browser Bundle (3.x series):</p>

110) 
111)     <ul>

112)     <li><a href="#WhereDidVidaliaGo">Where did the world map (Vidalia)

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

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

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

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

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

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

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

122)     <li><a href="#TBBSourceCode">Where is the source code for the bundle? How do

123)     I verify a build?</a></li>

124)     </ul>
125) 

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

127) 

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

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

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

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

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

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

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

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

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

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

143)     <li><a href="#WarningsAboutSOCKSandDNSInformationLeaks">I keep seeing
144)     these warnings about SOCKS and DNS information leaks. Should I

145)     worry?</a></li>

146)     <li><a href="#SocksAndDNS">How do I check if my application that uses

147)     SOCKS is leaking DNS requests?</a></li>

148)     </ul>

149) 

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

151)     <ul>

152) 
153)     <li><a href="#HowDoIDecide">How do I decide if I should run a relay?
154)     </a></li>

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

202)     <li><a href="#RelayMemory">Why is my Tor relay using so much memory?
203)     </a></li>
204)     <li><a href="#BetterAnonymity">Do I get better anonymity if I run a relay?
205)     </a></li>

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

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

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

210)     </ul>

211) 

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

213) 

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

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

217)     </ul>

218) 

219)     <p>Development:</p>

220) 

221)     <ul>

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

223)     mean?</a></li>
224)     <li><a href="#PrivateTorNetwork">How do I set up my own private
225)     Tor network?</a></li>

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

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

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

230)     into Tor?</a></li>
231)     </ul>
232) 

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

234)     <ul>

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

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

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

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

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

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

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

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

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

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

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

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

248)     connections?</a></li>
249)     <li><a href="#PowerfulBlockers">What about powerful blocking mechanisms
250)     </a></li>

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

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

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

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

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

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

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

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

259)     </ul>

260) 

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

262) 

263)     <ul>
264)     <li><a href="#EverybodyARelay">You should make every Tor user be a
265)     relay.</a></li>

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

289)     </ul>

290) 

291)     <p>Abuse:</p>

292)     <ul>

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

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

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

299)     </ul>

300) 

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

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

304) 

305)     <hr>

306) 

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

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

309) 

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

312) 

313)     <p>
314)     The name "Tor" can refer to several different components.
315)     </p>

316) 

317)     <p>

318)     The Tor software is a program you can run on your computer that
319) helps keep
320)     you safe on the Internet. Tor protects you by bouncing your
321) communications

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

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

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

326)     from learning your physical location. This set of volunteer relays
327) is
328)     called the Tor network. You can read more about how Tor works on the
329) <a

330)     href="<page about/overview>">overview page</a>.
331)     </p>

332) 

333)     <p>

334)     The Tor Project is a non-profit (charity) organization that
335) maintains

336)     and develops the Tor software.
337)     </p>

338) 

339)     <hr>

340) 

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

342)     <h3><a class="anchor" href="#Torisdifferent">How is Tor different
343) from other proxies?</a></h3>
344)     <p>
345)     A typical proxy provider sets up a server somewhere on the Internet
346) and
347) allows you to use it to relay your traffic.  This creates a simple, easy
348) to
349) maintain architecture.  The users all enter and leave through the same
350) server.
351) The provider may charge for use of the proxy, or fund their costs
352) through
353) advertisements on the server.  In the simplest configuration, you don't
354) have to
355) install anything.  You just have to point your browser at their proxy
356) server.
357) Simple proxy providers are fine solutions if you do not want protections
358) for
359) your privacy and anonymity online and you trust the provider from doing
360) bad
361) things.  Some simple proxy providers use SSL to secure your connection
362) to them.
363) This may protect you against local eavesdroppers, such as those at a
364) cafe with

365) free wifi Internet.
366)     </p>
367)     <p>

368)     Simple proxy providers also create a single point of failure.  The
369) provider
370) knows who you are and where you browse on the Internet.  They can see
371) your
372) traffic as it passes through their server.  In some cases, they can even
373) see

374) inside your

375) encrypted traffic as they relay it to your banking site or to ecommerce
376) stores.

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

378) watching your traffic, injecting their own advertisements into your
379) traffic

380) stream, and recording your personal details.

381)     </p>
382)     <p>

383)     Tor passes your traffic through at least 3 different servers before
384) sending
385) it on to the destination. Because there's a separate layer of encryption
386) for
387) each of the three relays, Tor does not modify, or even know, what you
388) are
389) sending into it.  It merely relays your traffic, completely encrypted
390) through
391) the Tor network and has it pop out somewhere else in the world,
392) completely
393) intact.  The Tor client is required because we assume you trust your
394) local
395) computer.  The Tor client manages the encryption and the path chosen
396) through
397) the network.  The relays located all over the world merely pass
398) encrypted

399) packets between themselves.</p>

400)     <p>
401)     <dl>

402)     <dt>Doesn't the first server see who I am?</dt><dd>Possibly. A bad
403) first of
404) three servers can see encrypted Tor traffic coming from your computer.
405) It
406) still doesn't know who you are and what you are doing over Tor.  It
407) merely sees
408) "This IP address is using Tor".  Tor is not illegal anywhere in the
409) world, so
410) using Tor by itself is fine.  You are still protected from this node
411) figuring

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

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

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

418) e-commerce website, or encrypted mail connections, etc, it will only
419) know the
420) destination.  It won't be able to see the data inside the traffic
421) stream.  You

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

424)     </dl>
425)     </p>

426) 

427)     <hr>

428) 

429) 

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

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

433) 

434)     <p>

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

439)     </p>
440)     <p>
441)     There are plenty of other programs you can use with Tor,
442)     but we haven't researched the application-level anonymity

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

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

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

446)     specific applications</a>.

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

449) 

450)     <hr>

451) 

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

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

455) 

456)     <p>
457)     Because Tor is the onion routing network. When we were starting the
458)     new next-generation design and implementation of onion routing in
459)     2001-2002, we would tell people we were working on onion routing,
460)     and they would say "Neat. Which one?" Even if onion routing has
461)     become a standard household term, Tor was born out of the actual <a
462)     href="http://www.onion-router.net/">onion routing project</a> run by
463)     the Naval Research Lab.
464)     </p>

465) 

466)     <p>
467)     (It's also got a fine translation from German and Turkish.)
468)     </p>

469) 

470)     <p>

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

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

474)     spot people who haven't read any of our website (and have instead
475) learned
476)     everything they know about Tor from news articles) by the fact that
477) they

478)     spell it wrong.
479)     </p>

480) 

481)     <hr>

482) 

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

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

486) 

487)     <p>

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

492)     </p>

493) 

494)     <p>
495)     We think that putting a backdoor in Tor would be tremendously

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

497)     software in general. If we ever put a deliberate backdoor in our
498)     security software, it would ruin our professional reputations.
499)     Nobody would trust our software ever again — for excellent
500)     reason!

501)     </p>

502) 

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

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

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

513)     </p>

514) 

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

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

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

519)     </p>

520) 

521)     <hr>

522) 

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

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

526) 

527)     <p>
528)     Yes.
529)     </p>

530) 

531)     <p>

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

535)     ask us for specific permission.
536)     </p>

537) 

538)     <p>

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

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

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

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

544) 

545)     <p>

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

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

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

549)     href="https://www.mozilla.org/en-US/firefox/organizations/">Firefox

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

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

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

557)     </p>

558) 

559)     <p>

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

563)     </p>

564) 

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

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

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

572) 

573)     <hr>

574) 

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

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

578) 

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

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

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

584)     <li>Read through the <a

585) 
586) href="https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-talk">
587) tor-talk

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

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

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

592)     <li>Send an email to <a

593) 
594) href="mailto:help@rt.torproject.org">help@rt.torproject.org</a>.</li>
595)     <li>If all else fails, try <a href="<page about/contact>">contacting
596) us</a> directly.</li>

597)     </ol>

598) 

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

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

602) 

603)     <hr>

604) 

605)     <a id="Forum"></a>
606)     <h3><a class="anchor" href="#Forum">Is there a Tor forum?</a></h3>
607) 

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

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

610)     </p>
611) 
612)     <hr>
613) 

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

616) 

617)     <p>
618)     There are many reasons why the Tor network is currently slow.
619)     </p>

620) 

621)     <p>

622)     Before we answer, though, you should realize that Tor is never going
623) to
624)     be blazing fast. Your traffic is bouncing through volunteers'
625) computers
626)     in various parts of the world, and some bottlenecks and network
627) latency

628)     will always be present. You shouldn't expect to see university-style
629)     bandwidth through Tor.
630)     </p>

631) 

632)     <p>

633)     But that doesn't mean that it can't be improved. The current Tor
634) network
635)     is quite small compared to the number of people trying to use it,
636) and
637)     many of these users don't understand or care that Tor can't
638) currently

639)     handle file-sharing traffic load.
640)     </p>

641) 

642)     <p>
643)     For the much more in-depth answer, see <a

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

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

647)     to go with it.
648)     </p>

649) 

650)     <p>
651)     What can you do to help?
652)     </p>

653) 

654)     <ul>

655) 

656)     <li>

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

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

663) 

664)     <li>

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

667)     especially need people to help make it easier to configure your Tor
668)     as a relay. Also, we need help with clear simple documentation to
669)     walk people through setting it up.
670)     </li>

671) 

672)     <li>

673)     There are some bottlenecks in the current Tor network. Help us
674) design
675)     experiments to track down and demonstrate where the problems are,
676) and

677)     then we can focus better on fixing them.
678)     </li>

679) 

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

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

686)     get to spend more time on it.
687)     </li>

688) 

689)     <li>

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

694)     getinvolved/volunteer>">look at our volunteer page</a>.
695)     </li>

696) 

697)     <li>

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

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

701)     competition's websites discreetly, or to connect back to the home
702) servers
703)     when on the road without revealing affiliations? If your
704) organization has
705)     an interest in keeping the Tor network working, please contact them
706) about
707)     supporting Tor. Without sponsors, Tor is going to become even
708) slower.

709)     </li>

710) 

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

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

715)     cause</a>. It adds up!
716)     </li>

717) 

718)     </ul>

719) 

720)     <hr>

721) 

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

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

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

725) 
726)     <p>

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

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

733)     </p>
734) 
735)     <hr>
736) 

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

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

740) 

741)     <p>

742)     The Tor network's <a

743) 
744) href="https://metrics.torproject.org/network.html#networksize">several

745)     thousand</a> relays push <a
746)     href="https://metrics.torproject.org/network.html#bandwidth">over
747)     1GB per second on average</a>. We have <a

748) 
749) href="https://metrics.torproject.org/users.html#direct-users">several

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

752)     </p>

753) 

754)     <p>

755)     There are six main development/maintenance pushes that need
756) attention:

757)     </p>

758) 

759)     <ul>

760) 

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

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

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

768) 

769)     <li>

770)     User support: With this many users, a lot of people are asking
771) questions
772)     all the time, offering to help out with things, and so on. We need
773) good
774)     clean docs, and we need to spend some effort coordinating
775) volunteers.

776)     </li>

777) 

778)     <li>

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

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

782)     reminders to upgrade, and so on. The network itself is a commons,
783) and
784)     somebody needs to spend some energy making sure the relay operators
785) stay
786)     happy. We also need to work on stability on some platforms —
787) e.g.,

788)     Tor relays have problems on Win XP currently.

789)     </li>

790) 

791)     <li>

792)     Usability: Beyond documentation, we also need to work on usability
793) of the
794)     software itself. This includes installers, clean GUIs, easy
795) configuration
796)     to interface with other applications, and generally automating all
797) of
798)     the difficult and confusing steps inside Tor. We've got a start on
799) this
800)     with the <a href="<page projects/vidalia>">Vidalia GUI</a>, but much
801) more work

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

804) 

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

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

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

812) 

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

818)     critical <a href="<page getinvolved/volunteer>#Research">Tor
819) research questions</a>
820)     that will help us figure out how to make Tor secure against the
821) variety of
822)     attacks out there. Of course, there are more research questions
823) waiting

824)     behind these.
825)     </li>

826) 

827)     </ul>

828) 

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

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

833)     can keep up</a>.

834)     Now would be an excellent time to add a few more developers to the
835) effort

836)     so we can continue to grow the network.
837)     </p>

838) 

839)     <p>
840)     We are also excited about tackling related problems, such as
841)     censorship-resistance.
842)     </p>

843) 

844)     <p>

845)     We are proud to have <a href="<page about/sponsors>">sponsorship and
846) support</a>
847)     from the Omidyar Network, the International Broadcasting Bureau,
848) Bell
849)     Security Solutions, the Electronic Frontier Foundation, several
850) government

851)     agencies and research groups, and hundreds of private contributors.
852)     </p>

853) 

854)     <p>

855)     However, this support is not enough to keep Tor abreast of changes
856) in the
857)     Internet privacy landscape. Please <a href="<page
858) donate/donate>">donate</a>
859)     to the project, or <a href="<page about/contact>">contact</a> our
860) executive

861)     director for information on making grants or major donations.
862)     </p>

863) 

864)     <hr>
865) 
866) 
867)     <a id="Mobile"></a>

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

869)     device?</a></h3>
870) 
871)     <p>

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

875)     working to make this a reality in the future.
876)     </p>
877) 

878)     <hr>
879) 

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

883)     <p>

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

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

889)     </p>
890)     <p>

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

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

895)     diversity in your entry nodes — and thus the most security
896)     — as well as the most robustness in your connectivity, you'll
897)     want to let it connect to all of them.
898)     See the FAQ entry on <a href="#FirewallPorts">firewalled ports</a> if
899)     you want to explicitly tell your Tor client which ports are reachable
900)     for you.
901)     </p>

902) 

903)     <hr>

904) 

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

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

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

908) 
909)     <p>

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

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

913)     </p>

914) 

915)     <hr>

916) 

917)     <a id="FTP"></a>
918)     <h3><a class="anchor" href="#FTP">How do I use my browser for ftp with Tor?
919)     </a></h3>
920) 

921)     <p>

922)     Use the <a href="https://torproject.org/projects/torbrowser.html">Tor
923)     Browser Bundle</a>. If you want a separate application for an
924)     ftp client, we've heard good things about  FileZilla for Windows. You can
925)     configure it to point to Tor as a "socks4a" proxy on "localhost" port
926)     "9050".

927)     </p>

928) 

929)     <hr>

930) 

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

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

933)     information from the data my application sends?</a></h3>
934) 

935)     <p>No, it doesn't. You need to use a separate program that understands
936)     your application and protocol and knows how to clean or "scrub" the data
937)     it sends. The Tor Browser Bundle tries to keep application-level data,
938)     like the user-agent string, uniform for all users. The Tor Browser can't
939)     do anything about text that you type into forms, though. <a

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

941)     careful and be smart.</a>
942)     </p>
943) 
944)     <hr>
945) 

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

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

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

949) 

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

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

953)     <hr>

954) 

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

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

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

958)     <p>

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

960)     </p>
961)     <pre>
962) Issued Certificate
963) Version: 3
964) Serial Number: 09 48 B1 A9 3B 25 1D 0D B1 05 10 59 E2 C2 68 0A
965) Not Valid Before: 2013-10-22
966) Not Valid After: 2016-05-03
967) Certificate Fingerprints
968) SHA1: 84 24 56 56 8E D7 90 43 47 AA 89 AB 77 7D A4 94 3B A1 A7 D5
969) MD5: A4 16 66 80 AE B9 A4 EC AA 88 01 1B 6F B9 EB CB

970)     </pre>

971) <br>
972)     <p>
973) blog.torproject.org SSL certificate from RapidSSL:

974)     </p>

975)     <pre>
976) Issued Certificate
977) Version: 3
978) Serial Number: 05 CA 2A A9 A5 D6 ED 44 C7 2D 88 1A 18 B0 E7 DC
979) Not Valid Before: 2014-04-09
980) Not Valid After: 2017-06-14
981) Certificate Fingerprints
982) SHA1: DE 20 3D 46 FD C3 68 EB BA 40 56 39 F5 FA FD F5 4E 3A 1F 83
983) MD5: 8A 8A A2 5E D9 7F 84 4C 8F 00 3B 43 E0 2D E6 4D
984)     </pre>

985)     <hr>
986) 

987)     <a id="CompilationAndInstallation"></a>
988)     <h2><a class="anchor">Compilation And Installation:</a></h2>
989) 

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

991)     <h3><a class="anchor" href="#HowUninstallTor">How do I uninstall
992) Tor?</a></h3>
993) 
994)     <p>
995)     Tor Browser does not install itself in the classic sense of
996) applications. You just simply delete the folder or directory named "Tor
997) Browser" and it is removed from your system.
998)     </p>

999) 

1000)     <p>

1001)     If this is not related to Tor Browser, uninstallation depends
1002) entirely on how you installed it and which operating system you
1003)     have. If you installed a package, then hopefully your package has a
1004) way to

1005)     uninstall itself. The Windows packages include uninstallers.

1006)     </p>

1007) 

1008)     <p>
1009)     For Mac OS X, follow the <a
1010)     href="<page docs/tor-doc-osx>#uninstall">uninstall directions</a>.
1011)     </p>

1012) 

1013)     <p>

1014)     If you installed by source, I'm afraid there is no easy uninstall
1015) method. But
1016)     on the bright side, by default it only installs into /usr/local/ and
1017) it should

1018)     be pretty easy to notice things there.
1019)     </p>

1020) 

1021)     <hr>

1022) 

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

1024)     <h3><a class="anchor" href="#PGPSigs">What are these "sig" files on
1025) the download page?</a></h3>

1026) 

1027)     <p>

1028)     These are PGP signatures, so you can verify that the file you've
1029) downloaded is

1030)     exactly the one that we intended you to get.
1031)     </p>

1032) 

1033)     <p>
1034)     Please read the <a

1035)     href="<page docs/verifying-signatures>">verifying signatures</a>
1036) page for details.

1037)     </p>

1038) 

1039) <hr>
1040) 
1041) <a id="GetTor"></a>
1042) <h3><a class="anchor" href="#GetTor">Your website is blocked in my
1043) country. How do I download Tor?</a></h3>
1044) 
1045) <p>
1046) Some government or corporate firewalls censor connections to Tor's
1047) website. In those cases, you have three options. First, get it from

1048) a friend &mdash; the <a href="<page projects/torbrowser>">Tor Browser

1049) Bundle</a> fits nicely on a USB key. Second, find the <a

1050) href="https://encrypted.google.com/search?q=tor+mirrors">google
1051) cache</a>

1052) for the <a href="<page getinvolved/mirrors>">Tor mirrors</a> page
1053) and see if any of those copies of our website work for you. Third,

1054) you can download Tor Browser via email: log in to your email account 
1055) and send an email to '<tt>gettor@torproject.org</tt>' with one of the 
1056) following words in the body of the message: <tt>windows</tt>, 
1057) <tt>osx</tt> or <tt>linux</tt> (case insensitive). 
1058) You will receive a reply with links from popular cloud services to 
1059) download Tor Browser for Windows, Mac OSX or Linux, depending on the 
1060) option you chose. Currently, the only cloud service supported is 
1061) Dropbox. If you send a blank message or anything different from the
1062) options mentioned, you will receive a help message with detailed
1063) instructions to ask for Tor Browser via email. See 
1064) <a href="../projects/gettor.html">GetTor</a> section for more 

1065) information.

1066) </p>
1067) 
1068) <p>

1069) Be sure to <a href="<page docs/verifying-signatures>">verify the
1070) signature</a>

1071) of any package you download, especially when you get it from somewhere
1072) other than our official HTTPS website.

1073) </p>
1074) 

1075)     <hr>

1076) 

1077)     <a id="VirusFalsePositives"></a>

1078)     <h3><a class="anchor" href="#VirusFalsePositives">Why does my
1079)     Tor executable appear to have a virus or spyware?</a></h3>

1080)     <p>

1081)     Sometimes, overzealous Windows virus and spyware detectors trigger on
1082)     some parts of the Tor Windows binary. Our best guess is that these are
1083)     false positives — after all, the anti-virus and anti-spyware business is
1084)     just a guessing game anyway. You should contact your vendor and explain
1085)     that you have a program that seems to be triggering false positives. Or

1086)     pick a better vendor.
1087)     </p>

1088)     <p>In the meantime, we encourage you to not just take our word for it.
1089)     Our job is to provide the source; if you're concerned, please do

1090)     recompile it yourself.</p>
1091) 
1092)     <hr>
1093) 

1094)     <a id="tarballs"></a>

1095)     <h3><a class="anchor" href="#tarballs">How do I open a .tar.gz

1096)     or .tar.xz file?</a></h3>

1097) 
1098)     <p>
1099)     Tar is a common archive utility for Unix and Linux systems. If your

1100)     system has a mouse, you can usually open them by double clicking.
1101)     Otherwise open a command prompt and execute</p>

1102)     <pre>tar xzf &lt;FILENAME&gt;.tar.gz</pre> or <pre>tar xJf &lt;FILENAME&gt;.tar.xz</pre>

1103)     <p>

1104)     as documented on tar's man page.

1105)     </p>
1106) 
1107)     <hr>
1108) 

1109)     <a id="LiveCD"></a>

1110)     <h3><a class="anchor" href="#LiveCD">Is there a LiveCD or other
1111) bundle that includes Tor?</a></h3>

1112) 

1113)     <p>

1114)     Yes.  Use <a href="https://tails.boum.org/">The Amnesic Incognito

1115)     Live System</a> or <a href="<page projects/torbrowser>">the Tor
1116) Browser

1117)     Bundle</a>.

1118)     </p>

1119) 
1120) <hr>
1121) 

1122) <a id="TBBGeneral"></a>
1123) <h2><a class="anchor">Tor Browser Bundle (general):</a></h2>
1124) 

1125) <a id="TBBFlash"></a>

1126) <h3><a class="anchor" href="#TBBFlash">Why can't I view videos on
1127) YouTube

1128) and other Flash-based sites?</a></h3>

1129) 
1130) <p>

1131) YouTube and similar sites require third party browser plugins such as Flash.
1132) Plugins operate independently from Firefox and can perform
1133) activity on your computer that ruins your anonymity. This includes
1134) but is not limited to: <a href="http://decloak.net">completely disregarding
1135) proxy settings</a>, querying your <a

1136) href="http://forums.sun.com/thread.jspa?threadID=5162138&messageID=9618376">
1137) local IP address</a>, and <a

1138) href="http://epic.org/privacy/cookies/flash.html">storing their own
1139) cookies</a>. It is possible to use a LiveCD solution such as

1140) or <a href="https://tails.boum.org/">The Amnesic Incognito Live System</a>
1141) that creates a secure, transparent proxy to protect you from proxy bypass,
1142) however issues with local IP address discovery and Flash cookies still remain.

1143) </p>

1144) 
1145) <p>

1146) <a href="https://www.youtube.com/html5">YouTube offers experimental HTML5 video

1147) support</a> for many of their videos. Often you can get the HTML5 version of
1148) videos that don't want to play by grabbing the YouTube URL from the "Embed"

1149) code under a video's "Share" option. The link switches out a URL that looks</p>
1150) <pre>https://www.youtube.com/watch?v=CJNxbpbHA-I</pre>
1151) <p>to something that looks like</p>
1152) <pre>https://www.youtube.com/embed/CJNxbpbHA-I</pre>

1153) 

1154) <hr>
1155) 

1156) <a id="Ubuntu"></a>
1157) <h3><a class="anchor" href="#Ubuntu">

1158) I'm using Ubuntu and I can't start Tor Browser.</a></h3>

1159) <p>

1160) You'll need to tell Ubuntu that you want the ability to execute shell scripts
1161) from the graphical interface. Open "Files" (Unity's explorer), open
1162) Preferences-> Behavior Tab -> Set "Run executable text files when they are

1163) opened" to "Ask every time", then OK.

1164) </p>
1165) <p>You can also start the Tor Browser from the command line by running </p>

1166) <pre>./start-tor-browser</pre>

1167) <p>
1168) from inside the Tor Browser directory.
1169) </p>
1170) 

1171) <hr>
1172) 

1173) <a id="SophosOnMac"></a>
1174) <h3><a class="anchor" href="#SophosOnMac">I'm using the Sophos anti-virus

1175)     software on my Mac, and Tor starts but I can't browse anywhere.</a></h3>

1176) <p>

1177) You'll need to modify Sophos anti-virus so that Tor can connect to the
1178) internet. Go to Preferences -> Web Protection -> General, and turn off

1179) the protections for "Malicious websites" and "Malicious downloads".
1180) </p>

1181) <p>

1182) We encourage affected Sophos users to contact Sophos support about

1183) this issue.
1184) </p>

1185) 

1186) <hr>
1187) 

1188) <a id="XPCOMError"></a>

1189) <h3><a class="anchor" href="#XPCOMError">When I start Tor Browser I get an 
1190) error message: "Cannot load XPCOM".</a></h3>

1191) 
1192) <p>

1193) This <a 
1194) href="https://trac.torproject.org/projects/tor/ticket/10789">problem</a> is 
1195) specifically caused by the Webroot SecureAnywhere Antivirus software. 
1196) From the Webroot control panel, go to Identity Protection &rarr; Application 
1197) Protection, and set all the files in your Tor Browser folder to 'Allow'. 
1198) We encourage affected Webroot users to contact Webroot support about this 
1199) issue.

1200) </p>

1201) 
1202) <hr>
1203) 

1204) <a id="TBBOtherExtensions"></a>
1205) <h3><a class="anchor" href="#TBBOtherExtensions">Can I install other
1206) Firefox extensions?</a></h3>
1207) 
1208) <p>

1209) The Tor Browser is free software, so there is nothing preventing you from
1210) modifying it any way you like. However, we do not recommend installing any
1211) additional Firefox add-ons with the Tor Browser Bundle. Add-ons can break
1212) your anonymity in a number of ways, including browser fingerprinting and

1213) bypassing proxy settings.

1214) </p>

1215) <p>

1216) Some people have suggested we include ad-blocking software or
1217) anti-tracking software with the Tor Browser Bundle. Right now, we do not
1218) think that's such a good idea. The Tor Browser Bundle aims to provide
1219) sufficient privacy that additional add-ons to stop ads and trackers are
1220) not necessary. Using add-ons like these may cause some sites to break, which

1221) <a href="https://www.torproject.org/projects/torbrowser/design/#philosophy">

1222) we don't want to do</a>. Additionally, maintaining a list of "bad" sites that
1223) should be black-listed provides another opportunity to uniquely fingerprint
1224) users.

1225) </p>

1226) 

1227) <hr>
1228) 

1229) <a id="TBBJavaScriptEnabled"></a>

1230) <a id="TBBCanIBlockJS"></a>

1231) <h3><a class="anchor" href="#TBBJavaScriptEnabled">Why is NoScript
1232) configured to allow JavaScript by default in the Tor Browser Bundle?
1233) Isn't that unsafe?</a></h3>

1234) 
1235) <p>
1236) We configure NoScript to allow JavaScript by default in the Tor
1237) Browser Bundle because many websites will not work with JavaScript
1238) disabled.  Most users would give up on Tor entirely if a website
1239) they want to use requires JavaScript, because they would not know
1240) how to allow a website to use JavaScript (or that enabling
1241) JavaScript might make a website work).
1242) </p>
1243) 

1244) <p>
1245) There's a tradeoff here. On the one hand, we should leave
1246) JavaScript enabled by default so websites work the way
1247) users expect. On the other hand, we should disable JavaScript
1248) by default to better protect against browser vulnerabilities (<a

1249) href="https://blog.torproject.org/blog/tor-security-advisory-old-tor-browser-bundles-vulnerable">
1250) not just a theoretical concern!</a>). But there's a third issue: websites

1251) can easily determine whether you have allowed JavaScript for them,
1252) and if you disable JavaScript by default but then allow a few websites
1253) to run scripts (the way most people use NoScript), then your choice of
1254) whitelisted websites acts as a sort of cookie that makes you recognizable
1255) (and distinguishable), thus harming your anonymity.
1256) </p>

1257) 
1258) <p>

1259) Ultimately, we want the default Tor bundles to use
1260) a combination of firewalls (like the iptables rules
1261) in <a href="https://tails.boum.org/">Tails</a>) and <a
1262) href="https://trac.torproject.org/projects/tor/ticket/7680">sandboxes</a>
1263) to make JavaScript not so scary. In
1264) the shorter term, TBB 3.0 will hopefully <a
1265) href="https://trac.torproject.org/projects/tor/ticket/9387">allow users
1266) to choose their JavaScript settings more easily</a> &mdash; but the
1267) partitioning concern will remain.

1268) </p>
1269) 
1270) <p>

1271) Until we get there, feel free to leave JavaScript on or off depending
1272) on your security, anonymity, and usability priorities.

1273) </p>
1274) 
1275) <hr>
1276) 

1277) <a id="TBBOtherBrowser"></a>
1278) <h3><a class="anchor" href="#TBBOtherBrowser">I want to use
1279) Chrome/IE/Opera/etc with Tor.</a></h3>
1280) 
1281) <p>

1282) In short, using any browser besides Tor Browser with Tor is a

1283) really bad idea.
1284) </p>
1285) 
1286) <p>

1287) Our efforts to work with the Chrome team to <a
1288) href="https://blog.torproject.org/blog/google-chrome-incognito-mode-tor-and-fingerprinting">add
1289) missing APIs</a> were unsuccessful, unfortunately. Currently, it is impossible
1290) to use other browsers and get the same level of protections as when using the
1291) Tor Browser.

1292) </p>
1293) 
1294) <hr>
1295) 

1296) <a id="GoogleCAPTCHA"></a>
1297) <h3><a class="anchor" href="#GoogleCAPTCHA">Google makes me solve a
1298) CAPTCHA or tells me I have spyware installed.</a></h3>

1299) 
1300) <p>
1301) This is a known and intermittent problem; it does not mean that Google
1302) considers Tor to be spyware.
1303) </p>
1304) 
1305) <p>

1306) When you use Tor, you are sending queries through exit relays that are

1307) also shared by thousands of other users. Tor users typically see this
1308) message when many Tor users are querying Google in a short period of time.
1309) Google interprets the high volume of traffic from a single IP address
1310) (the exit relay you happened to pick) as somebody trying to "crawl" their
1311) website, so it slows down traffic from that IP address for a short time.

1312) </p>
1313) <p>
1314) An alternate explanation is that Google tries to detect certain
1315) kinds of spyware or viruses that send distinctive queries to Google
1316) Search. It notes the IP addresses from which those queries are received
1317) (not realizing that they are Tor exit relays), and tries to warn any
1318) connections coming from those IP addresses that recent queries indicate
1319) an infection.
1320) </p>
1321) 
1322) <p>

1323) To our knowledge, Google is not doing anything intentionally specifically

1324) to deter or block Tor use. The error message about an infected machine
1325) should clear up again after a short time.
1326) </p>
1327) 
1328) <hr />
1329) 

1330) <a id="ForeignLanguages"></a>
1331) <h3><a class="anchor" href="#ForeignLanguages">
1332) Why does Google show up in foreign languages?</a></h3>
1333) 
1334) <p>

1335)  Google uses "geolocation" to determine where in the world you are, so it
1336)  can give you a personalized experience. This includes using the language
1337)  it thinks you prefer, and it also includes giving you different results

1338)  on your queries.

1339) </p>
1340) <p>

1341) If you really want to see Google in English you can click the link that
1342) provides that. But we consider this a feature with Tor, not a bug --- the
1343) Internet is not flat, and it in fact does look different depending on

1344) where you are. This feature reminds people of this fact.

1345) </p>
1346) <p>

1347) Note that Google search URLs take name/value pairs as arguments and one
1348) of those names is "hl". If you set "hl" to "en" then Google will return
1349) search results in English regardless of what Google server you have been
1350) sent to. On a query this looks like:

1351) </p>

1352) <pre>https://encrypted.google.com/search?q=online%20anonymity&hl=en</pre>

1353) <p>

1354) Another method is to simply use your country code for accessing Google.
1355) This can be google.be, google.de, google.us and so on.

1356) </p>
1357) <hr />

1358) <a id="GmailWarning"></a>

1359) <h3><a class="anchor" href="#GmailWarning">Gmail warns me that my

1360) account may have been compromised.</a></h3>

1361) 
1362) <p>
1363) Sometimes, after you've used Gmail over Tor, Google presents a
1364) pop-up notification that your account may have been compromised.
1365) The notification window lists a series of IP addresses and locations
1366) throughout the world recently used to access your account.
1367) </p>
1368) 
1369) <p>
1370) In general this is a false alarm: Google saw a bunch of logins from

1371) different places, as a result of running the service via Tor, and
1372) decided

1373) it was a good idea to confirm the account was being accessed by it's
1374) rightful owner.
1375) </p>
1376) 
1377) <p>
1378) Even though this may be a biproduct of using the service via tor,
1379) that doesn't mean you can entirely ignore the warning. It is
1380) <i>probably</i> a false positive, but it might not be since it is
1381) possible for someone to hijack your Google cookie.
1382) </p>
1383) 
1384) <p>
1385) Cookie hijacking is possible by either physical access to your computer
1386) or by watching your network traffic.  In theory only physical access
1387) should compromise your system because Gmail and similar services
1388) should only send the cookie over an SSL link. In practice, alas, it's <a

1389) href="http://fscked.org/blog/fully-automated-active-https-cookie-
1390) hijacking">

1391) way more complex than that</a>.
1392) </p>
1393) 
1394) <p>
1395) And if somebody <i>did</i> steal your google cookie, they might end
1396) up logging in from unusual places (though of course they also might
1397) not). So the summary is that since you're using Tor, this security
1398) measure that Google uses isn't so useful for you, because it's full of
1399) false positives. You'll have to use other approaches, like seeing if
1400) anything looks weird on the account, or looking at the timestamps for
1401) recent logins and wondering if you actually logged in at those times.
1402) </p>
1403) 
1404) <hr>
1405) 

1406) <a id="NeedToUseAProxy"></a>

1407) <h3><a class="anchor" href="#NeedToUseAProxy">My internet connection

1408) requires an HTTP or SOCKS Proxy</a></h3>

1409) 
1410) <p>

1411) You can set Proxy IP address, port, and authentication information in
1412) Tor Browser's Network Settings. If you're using Tor another way, check
1413) out the HTTPProxy and HTTPSProxy config options in the <a

1414) href="<page docs/tor-manual>">man page</a>,

1415) and modify your torrc file accordingly. You will need an HTTP proxy for
1416) doing GET requests to fetch the Tor directory, and you will need an
1417) HTTPS proxy for doing CONNECT requests to get to Tor relays. (It's fine
1418) if they're the same proxy.) Tor also recognizes the torrc options
1419) Socks4Proxy and Socks5Proxy.

1420) </p>
1421) <p>

1422) Also read up on the HTTPProxyAuthenticator and HTTPSProxyAuthenticator
1423) options if your proxy requires auth. We only support basic auth currently,
1424) but if you need NTLM authentication, you may find <a
1425) href="http://archives.seul.org/or/talk/Jun-2005/msg00223.html">this post
1426) in the archives</a> useful.

1427) </p>
1428) <p>

1429) If your proxies only allow you to connect to certain ports, look at the
1430) entry on <a href="#FirewallPorts">Firewalled clients</a> for how
1431) to restrict what ports your Tor will try to access.

1432) </p>
1433) 
1434) <hr>
1435) 

1436) 
1437) <a id="TBBSocksPort"></a>
1438) <h3><a class="anchor" href="#TBBSocksPort">
1439) I want to run another application through Tor.</a></h3>
1440) 
1441) <p>
1442) If you are trying to use some external application with Tor, step zero
1443) should be to <a href="<page download/download>#warning">reread the set
1444) of warnings</a> for ways you can screw up. Step one should be to try
1445) to use a SOCKS proxy rather than an HTTP proxy.
1446) Typically Tor listens for SOCKS connections on port 9050. Tor Browser listens
1447) on port 9150.
1448) </p>
1449) 
1450) <p>
1451) If your application doesn't support SOCKS proxies, feel free to install <a
1452) href="http://www.privoxy.org/">privoxy</a>.
1453) However, please realize that this approach is not recommended for novice
1454) users. Privoxy has an <a
1455) href="http://www.privoxy.org/faq/misc.html#TOR">example
1456) configuration</a> of Tor and Privoxy.
1457) </p>
1458) 
1459) <p>

1460) If you're unable to use the application's native proxy settings, all hope is

1461) not lost. See <a href="#CantSetProxy">below</a>.
1462) </p>
1463) 
1464) <hr>
1465) 

1466) <a id="CantSetProxy"></a>

1467) <h3><a class="anchor" href="#CantSetProxy">What should I do if I can't

1468) set a proxy with my application?</a></h3>
1469) 
1470) <p>

1471) On Unix, we recommend you give <a
1472) href="https://github.com/dgoulet/torsocks/">torsocks</a> a try.
1473) Alternative proxifying tools like <a
1474) href="http://www.dest-unreach.org/socat/">socat</a> and <a
1475) href="http://proxychains.sourceforge.net/">proxychains</a> are also

1476) available.</p>

1477) <p>
1478) The Windows way to force applications through Tor is less clear. <a
1479) href="http://freecap.ru/eng/">Some</a> <a
1480) href="http://www.freehaven.net/~aphex/torcap/">tools</a> have been <a

1481) href="http://www.crowdstrike.com/community-tools/index.html#tool-79">proposed

1482) </a>, but we'd also like to see further testing done here.

1483) </p>
1484) 
1485) <hr>
1486) 

1487) <a id="TBB3.x"></a>
1488) <h2><a class="anchor">Tor Browser Bundle (3.x series):</a></h2>

1489)     <a id="WhereDidVidaliaGo"></a>

1490)     <h3><a class="anchor" href="#WhereDidVidaliaGo">Where did the world map

1491)     (Vidalia) go?</a></h3>
1492) 

1493)     <p>Vidalia has been replaced with Tor Launcher, which is a Firefox
1494)     extension that provides similar functionality. Unfortunately, circuit
1495)     status reporting is still missing, but we are <a
1496)     href="https://trac.torproject.org/projects/tor/ticket/8641">working

1497)     on providing it</a>. </p>
1498) 

1499)     <p>In the meantime, we are providing standalone Vidalia packages for
1500)     people who still want the map. Windows and Linux versions are <a

1501)     href="https://people.torproject.org/~erinn/vidalia-standalone-bundles/">

1502)     available here</a>.</p>

1503) 

1504)     <p>To use these packages, extract them, then run the startup script.
1505)     On Windows, this is "Start Vidalia.exe". On Linux, it is start-vidalia.
1506)     They can be placed in a different directory from TBB (and likely should

1507)     be). </p>
1508) 

1509)     <p>This Vidalia package will only run properly if Tor Browser has already

1510)     been launched. You cannot start it before launching Tor Browser. </p>
1511) 

1512)     <p>MacOS is still under development, but in the mean time you can modify
1513)     your TBB 2.x to be a standalone Vidalia (and then use it after starting
1514)     TBB 3.x) by opening your TBB 2.x vidalia.conf file in an editor and

1515)     replacing its contents with just these lines:</p>
1516) 
1517)     <pre>
1518)     [General]
1519)     LanguageCode=en
1520) 
1521)     [Tor]
1522)     ControlPort=9151
1523)     TorExecutable=.
1524)     Torrc=.
1525)     DataDirectory=.
1526)     AuthenticationMethod=cookie

1527)     </pre>

1528) 
1529)     <hr>
1530) 
1531)     <a id="DisableJS"></a>
1532)     <h3><a class="anchor" href="#DisableJS">How do I disable JavaScript?</a>
1533)     </h3>
1534) 

1535)     <p>Alas, Mozilla decided to get rid of the config checkbox for JavaScript
1536)     from earlier Firefox versions. And since TBB 3.5 is based on Firefox 24
1537)     (FF17 is unmaintained), that means TBB 3.5 doesn't have the config

1538)     checkbox anymore either, which is unfortunate.</p>
1539) 

1540)     <p>The simplest way to disable JavaScript in TBB 3.5 is to click on the
1541)     Noscript "S" (between the green onion and the address bar), and select
1542)     "Forbid scripts globally". Note that vanilla NoScript actually whitelists
1543)     several domains even when you try to disable scripts globally, whereas

1544)     Tor Browser's NoScript configuration disables all of them. </p>
1545) 

1546)     <p>The more klunky way to disable JavaScript is to go to about:config,

1547)     find javascript.enabled, and set it to false.</p>
1548) 
1549)     <p>There is also a very simple addon available at addons.mozilla.org
1550)     called QuickJS, which provides a toolbar toggle for the javascript.enabled

1551)     about:config control. There are no configuration options for the addon,
1552)     it just switches the javascript.enabled entry between true and false and

1553)     provides a button for it. </p>
1554) 

1555)     <p>If you want to be extra safe, use both the about:config setting and

1556)     NoScript. </p>
1557) 

1558)     <p>As for whether you should disable it or leave it enabled, that's <a

1559)     href="#TBBJavaScriptEnabled">a tradeoff we leave to you</a>.</p>

1560) 
1561)     <hr>
1562) 
1563)     <a id="VerifyDownload"></a>
1564)     <h3><a class="anchor" href="#VerifyDownload">How do I verify the download
1565)     (sha256sums.txt)?</a></h3>
1566) 

1567)     <p>Instructions are on the <a
1568)     href="<page docs/verifying-signatures>#BuildVerification">verifying

1569)     signatures</a> page.</p>

1570) 
1571)     <hr>

1572) 

1573)     <a id="NewIdentityClosingTabs"></a>

1574)     <h3><a class="anchor" href="#NewIdentityClosingTabs">Why does "New

1575)     Identity" close all my open tabs?</a></h3>
1576) 
1577)     <p>

1578)     That's actually a feature, since it's discarding your application-level
1579)     browser data too. But it sure is a surprising feature, for people who

1580)     are used to Vidalia's "new identity" behavior.
1581)     </p>
1582) 
1583)     <p>

1584)     We're working on ways to make the behavior less surprising, e.g. a popup
1585)     warning or auto restoring tabs. See ticket <a
1586)     href="https://trac.torproject.org/projects/tor/ticket/9906">#9906</a> and
1587)     ticket <a
1588)     href="https://trac.torproject.org/projects/tor/ticket/10400">#10400</a>
1589)     to follow progress there.

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

1593)     In the mean time, you can get Vidalia's old "newnym" functionality by
1594)     attaching a Vidalia to your TBB 3.x. See the instructions <a
1595)     href="#WhereDidVidaliaGo">above</a>.

1596)     </p>
1597) 
1598)     <hr>
1599) 
1600)     <a id="ConfigureRelayOrBridge"></a>
1601)     <h3><a class="anchor" href="#ConfigureRelayOrBridge">How do I configure Tor as a relay or bridge?</a></h3>
1602) 
1603)     <p>

1604)     You've got three options.

1605)     </p>
1606) 
1607)     <p>

1608)     First (best option), if you're on Linux, you can install the system
1609)     Tor package (e.g. apt-get install tor) and then set it up to be a relay
1610)     (<a href="https://www.torproject.org/docs/tor-relay-debian">instructions</a>).

1611)     You can then use TBB independent of that.
1612)     </p>
1613) 
1614)     <p>

1615)     Second (simpler option), if you're on Windows, you can fetch the separate
1616)     "Vidalia relay bundle" or "Vidalia bridge bundle" from the download page
1617)     and then use that (again you can use TBB independent of it).

1618)     </p>
1619) 
1620)     <p>

1621)     Third (complex option), you can either hook your Vidalia up to TBB (as
1622)     described in the FAQ above) or edit your torrc file (in Data/Tor/torrc)
1623)     directly to add the following lines:

1624)     </p>
1625)     <pre>
1626)     ORPort 443
1627)     Exitpolicy reject *:*
1628)     BridgeRelay 1  # only add this line if you want to be a bridge
1629)     </pre>
1630)     <p>

1631)     If you've installed <a

1632)     href="<page projects/obfsproxy-debian-instructions>#instructions">Obfsproxy</a>,

1633)     you'll need to add one more line:
1634)     </p>
1635)     <pre>
1636)     ServerTransportPlugin obfs3 exec /usr/bin/obfsproxy managed
1637)     </pre>
1638)     <p>

1639)     This third option is pretty klunky right now; see e.g. <a
1640)     href="https://trac.torproject.org/projects/tor/ticket/10449">this bug</a>;
1641)     but we're hoping it will become an easy option in the future.

1642)     </p>
1643) 
1644)     <hr>
1645) 
1646)     <a id="Timestamps"></a>

1647)     <h3><a class="anchor" href="#Timestamps">Why are the file timestamps

1648)     from 2000?</a></h3>
1649) 

1650)     <p>One of the huge new features in TBB 3.x is the "deterministic build"
1651)     process, which allows many people to build the Tor Browser Bundle and
1652)     verify that they all make exactly the same package. See Mike's <a
1653)     href="https://blog.torproject.org/blog/deterministic-builds-part-one-cyberwar-and-global-compromise">first
1654)     blog</a> post for the motivation, and his <a

1655)     href="https://blog.torproject.org/blog/deterministic-builds-part-two-technical-details">second

1656)     blog post</a> for the technical details of how we do it.

1657)     </p>
1658) 

1659)     <p>Part of creating identical builds is having everybody use the same
1660)     timestamp. Mike picked the beginning of 2000 for that time. The reason

1661)     you might see 7pm in 1999 is because of time zones. </p>
1662) 
1663)     <hr>
1664) 

1665)     <a id="TBBSourceCode"></a>
1666)     <h3><a class="anchor" href="#TBBSourceCode">Where is the source code for the bundle? How do I verify a build?</a></h3>

1667) 
1668)     <p>

1669)     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>.

1670)     </p>
1671) 
1672) 

1673) <hr>
1674) 

1675) <a id="AdvancedTorUsage"></a>
1676) <h2><a class="anchor">Advanced Tor usage:</a></h2>
1677) 

1678) <a id="torrc"></a>

1679) <h3><a class="anchor" href="#torrc">I'm supposed to "edit my torrc".
1680) What does that mean?</a></h3>

1681) 
1682) <p>
1683) Tor installs a text file called torrc that contains configuration
1684) instructions for how your Tor program should behave. The default

1685) configuration should work fine for most Tor users.

1686) </p>

1687) <p>

1688) If you installed Tor Browser Bundle, look for

1689) <code>Data/Tor/torrc</code> inside your Tor Browser Bundle directory.
1690) On OS X, you must right-click or command-click on the browser bundle icon,
1691) and select "Show Package Contents" before the Tor Browser directories become
1692) visible.

1693) </p>
1694) <p>

1695) 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>

1696) 
1697) <p>

1698) Once you've changed your torrc, you will need to restart tor for the
1699) changes to take effect. (For advanced users, note that

1700) you actually only need to send Tor a HUP signal, not actually restart
1701) it.)

1702) </p>
1703) 
1704) <p>

1705) For other configuration options you can use, see the <a href="<page

1706) docs/tor-manual>">Tor manual page</a>. Have a look at <a

1707) href="https://gitweb.torproject.org/tor.git/tree/src/config/torrc.sample.in">

1708) the sample torrc file</a> for hints on common configurations. Remember, all
1709) lines beginning with # in torrc are treated as comments and have no effect

1710) on Tor's configuration.

1711) </p>
1712) 
1713) <hr>
1714) 

1715) <a id="Logs"></a>

1716) <h3><a class="anchor" href="#Logs">How do I set up logging, or see Tor's
1717) logs?</a></h3>

1718) 
1719) <p>

1720) If you installed a Tor bundle that includes Vidalia, then Vidalia has a

1721) window called "Message Log" that will show you Tor's log messages. Click
1722) on "Advanced" to see more details. You can click on "Settings" to change
1723) your log verbosity or save the messages to a file. You're all set.

1724) </p>
1725) 
1726) <p>
1727) If you're not using Vidalia, you'll have to go find the log files by

1728) hand. Here are some likely places for your logs to be:

1729) </p>
1730) 
1731) <ul>
1732) <li>On OS X, Debian, Red Hat, etc, the logs are in /var/log/tor/
1733) </li>

1734) <li>On Windows, there are no default log files currently. If you enable
1735) logs in your torrc file, they default to <code>\username\Application
1736) Data\tor\log\</code> or <code>\Application Data\tor\log\</code>
1737) </li>
1738) <li>If you compiled Tor from source, by default your Tor logs to <a
1739) href="http://en.wikipedia.org/wiki/Standard_streams">"stdout"</a>
1740) at log-level notice. If you enable logs in your torrc file, they
1741) default to <code>/usr/local/var/log/tor/</code>.

1742) </li>
1743) </ul>
1744) 
1745) <p>

1746) To change your logging setup by hand, <a href="#torrc">edit your
1747) torrc</a>

1748) and find the section (near the top of the file) which contains the
1749) following line:

1750) </p>
1751) 
1752) <pre>

1753) \## Logs go to stdout at level "notice" unless redirected by something
1754) \## else, like one of the below lines.

1755) </pre>

1756) 
1757) <p>

1758) For example, if you want Tor to send complete debug, info, notice, warn,

1759) and err level messages to a file, append the following line to the end
1760) of the section:
1761) </p>
1762) 
1763) <pre>
1764) Log debug file c:/program files/tor/debug.log
1765) </pre>
1766) 
1767) <p>

1768) Replace <code>c:/program files/tor/debug.log</code> with a directory
1769) and filename for your Tor log.

1770) </p>
1771) 
1772) <hr>
1773) 

1774) 
1775) <a id="LogLevel"></a>
1776) <h3><a class="anchor" href="#LogLevel">What log level should I use?</a></h3>
1777) 
1778) <p>

1779) There are five log levels (also called "log severities") you might see in

1780) Tor's logs:

1781) </p>
1782) 
1783) <ul>

1784)     <li>"err": something bad just happened, and we can't recover. Tor will

1785)     exit.</li>

1786)     <li>"warn": something bad happened, but we're still running. The bad
1787)     thing might be a bug in the code, some other Tor process doing something
1788)     unexpected, etc. The operator should examine the message and try to

1789)     correct the problem.</li>

1790)     <li>"notice": something the operator will want to know about.</li>

1791)     <li>"info": something happened (maybe bad, maybe ok), but there's

1792)     nothing you need to (or can) do about it.</li>

1793)     <li>"debug": for everything louder than info. It is quite loud indeed.</li>

1794) </ul>
1795) 
1796) <p>

1797) Alas, some of the warn messages are hard for ordinary users to correct -- the
1798) developers are slowly making progress at making Tor automatically react

1799) correctly for each situation.

1800) </p>
1801) 
1802) <p>

1803) We recommend running at the default, which is "notice". You will hear about

1804) important things, and you won't hear about unimportant things.

1805) </p>
1806) 
1807) <p>

1808) Tor relays in particular should avoid logging at info or debug in normal
1809) operation, since they might end up recording sensitive information in
1810) their logs.

1811) </p>
1812) 

1813) <hr>
1814) 

1815) <a id="DoesntWork"></a>

1816) <h3><a class="anchor" href="#DoesntWork">I installed Tor but it's not
1817) working.</a></h3>

1818) 
1819) <p>

1820) Once you've got the Tor bundle up and running, the first question to
1821) ask is whether your Tor client is able to establish a circuit.

1822) </p>
1823) 
1824) <p>If Tor can establish a circuit, the onion icon in

1825) Vidalia will turn green (and if you're running Tor Browser Bundle, it
1826) will
1827) automatically launch a browser for you). You can also check in the
1828) Vidalia

1829) Control Panel to make sure it says "Connected to the Tor
1830) network!" under Status. For those not using Vidalia, check your <a

1831) href="#Logs">Tor logs</a> for

1832) a line saying that Tor "has successfully opened a circuit. Looks like
1833) client functionality is working."
1834) </p>
1835) 
1836) <p>
1837) If Tor can't establish a circuit, here are some hints:
1838) </p>
1839) 
1840) <ol>
1841) <li>Are you sure Tor is running? If you're using Vidalia, you may have
1842) to click on the onion and select "Start" to launch Tor.</li>
1843) <li>Check your system clock. If it's more than a few hours off, Tor will

1844) refuse to build circuits. For Microsoft Windows users, synchronize your
1845) clock under the clock -> Internet time tab. In addition, correct the

1846) day and date under the 'Date & Time' Tab. Also make sure your time
1847) zone is correct.</li>

1848) <li>Is your Internet connection <a href="#FirewallPorts">firewalled
1849) by port</a>, or do you normally need to use a <a

1850) href="<#NeedToUseAProxy">proxy</a>?

1851) </li>

1852) <li>Are you running programs like Norton Internet Security or SELinux
1853) that

1854) block certain connections, even though you don't realize they do? They
1855) could be preventing Tor from making network connections.</li>
1856) <li>Are you in China, or behind a restrictive corporate network firewall
1857) that blocks the public Tor relays? If so, you should learn about <a

1858) href="<page docs/bridges>">Tor bridges</a>.</li>

1859) <li>Check your <a href="#Logs">Tor logs</a>. Do they give you any hints
1860) about what's going wrong?</li>

1861) </ol>
1862) 
1863) <hr />
1864) 

1865) <a id="TorCrash"></a>
1866) <h3><a class="anchor" href="#TorCrash">My Tor keeps crashing.</a></h3>
1867) <p>

1868)  We want to hear from you! There are supposed to be zero crash bugs in Tor.
1869)  This FAQ entry describes the best way for you to be helpful to us. But even
1870)  if you can't work out all the details, we still want to hear about it, so
1871)  we can help you track it down.

1872) </p>
1873) <p>

1874) First, make sure you're using the latest version of Tor (either the latest
1875) stable or the latest development version).

1876) </p>
1877) <p>

1878) Second, make sure your version of libevent is new enough. We recommend at
1879) least libevent 1.3a.

1880) </p>
1881) <p>

1882) Third, see if there's already an entry for your bug in the <a
1883) href="https://bugs.torproject.org/">Tor bugtracker</a>. If so,
1884) check if there are any new details that you can add.

1885) </p>
1886) <p>

1887) Fourth, is the crash repeatable? Can you cause the crash? Can
1888) you isolate some of the circumstances or config options that
1889) make it happen? How quickly or often does the bug show up?
1890) Can you check if it happens with other versions of Tor, for
1891) example the latest stable release?

1892) </p>
1893) <p>

1894) Fifth, what sort of crash do you get?

1895) </p>
1896) <ul>
1897) <li>

1898) Does your Tor log include an "assert failure"? If so, please
1899) tell us that line, since it helps us figure out what's going on.
1900) Tell us the previous couple of log messages as well, especially
1901) if they seem important.

1902) </li>
1903) <li>

1904) If it says "Segmentation fault - core dumped" then you need to
1905) do a bit more to track it down. Look for a file like "core" or
1906) "tor.core" or "core.12345" in your current directory, or in your
1907) Data Directory. If it's there, run "gdb tor core" and then "bt",
1908) and include the output. If you can't find a core, run "ulimit -c
1909) unlimited", restart Tor, and try to make it crash again. (This core
1910) thing will only work on Unix -- alas, tracking down bugs on Windows
1911) is harder. If you're on Windows, can you get somebody to duplicate

1912) your bug on Unix?)
1913) </li>
1914) <li>

1915) If Tor simply vanishes mysteriously, it probably is a segmentation
1916) fault but you're running Tor in the background (as a daemon) so you
1917) won't notice. Go look at the end of your log file, and look for a
1918) core file as above. If you don't find any good hints, you should
1919) consider running Tor in the foreground (from a shell) so you can
1920) see how it dies. Warning: if you switch to running Tor in the foreground,
1921) you might start using a different torrc file, with a different default
1922) Data Directory; see the <a href="#UpgradeOrMove">relay-upgrade FAQ entry</a>
1923) for details.

1924) </li>
1925) <li>

1926) If it's still vanishing mysteriously, perhaps something else is killing it?
1927) Do you have resource limits (ulimits) configured that kill off processes
1928) sometimes? (This is especially common on OpenBSD.) On Linux, try running
1929) "dmesg" to see if the out-of-memory killer removed your process. (Tor will
1930) exit cleanly if it notices that it's run out of memory, but in some cases
1931) it might not have time to notice.) In very rare circumstances, hardware
1932) problems could also be the culprit.

1933) </li>
1934) </ul>
1935) <p>

1936) Sixth, if the above ideas don't point out the bug, consider increasing your
1937) log level to "loglevel debug". You can look at the log-configuration FAQ
1938) entry for instructions on what to put in your torrc file. If it usually
1939) takes a long time for the crash to show up, you will want to reserve a whole
1940) lot of disk space for the debug log. Alternatively, you could just send
1941) debug-level logs to the screen (it's called "stdout" in the torrc), and then
1942) when it crashes you'll see the last couple of log lines it had printed.
1943) (Note that running with verbose logging like this will slow Tor down
1944) considerably, and note also that it's generally not a good idea security-wise
1945) to keep logs like this sitting around.)

1946) </p>
1947) 
1948) <hr />
1949) 

1950)     <a id="ChooseEntryExit"></a>

1951)     <h3><a class="anchor" href="#ChooseEntryExit">Can I control which
1952) nodes (or country) are used for entry/exit?</a></h3>

1953) 

1954)     <p>

1955)     Yes. You can set preferred entry and exit nodes as well as
1956)     inform Tor which nodes you do not want to use.

1957)     The following options can be added to your config file <a
1958)     href="#torrc">"torrc"</a> or specified on the command line:

1959)     </p>
1960)     <dl>
1961)       <dt><tt>EntryNodes $fingerprint,$fingerprint,...</tt></dt>

1962)         <dd>A list of preferred nodes to use for the first hop in the
1963) circuit, if possible.

1964)         </dd>
1965)       <dt><tt>ExitNodes $fingerprint,$fingerprint,...</tt></dt>

1966)         <dd>A list of preferred nodes to use for the last hop in the
1967) circuit, if possible.

1968)         </dd>
1969)       <dt><tt>ExcludeNodes $fingerprint,$fingerprint,...</tt></dt>

1970)         <dd>A list of nodes to never use when building a circuit.

1971)         </dd>
1972)       <dt><tt>ExcludeExitNodes $fingerprint,$fingerprint,...</tt></dt>

1973)         <dd>A list of nodes to never use when picking an exit.

1974)             Nodes listed in <tt>ExcludeNodes</tt> are automatically in
1975) this list.

1976)         </dd>
1977)     </dl>
1978)     <p>

1979)     <em>We recommend you do not use these</em>

1980)     — they are intended for testing and may disappear in future
1981) versions.

1982)     You get the best security that Tor can provide when you leave the
1983)     route selection to Tor; overriding the entry / exit nodes can mess
1984)     up your anonymity in ways we don't understand.

1985)     </p>
1986)     <p>

1987)     Note also that not every circuit is used to deliver traffic outside of
1988)     the Tor network. It is normal to see non-exit circuits (such as those
1989)     used to connect to hidden services, those that do directory fetches,
1990)     those used for relay reachability self-tests, and so on) that end at
1991)     a non-exit node. To keep a node from being used entirely, see
1992)     <tt>ExcludeNodes</tt> and <tt>StrictNodes</tt> in the

1993)     <a href="<page docs/tor-manual>">manual</a>.

1994)     </p>
1995)     <p>

1996)     Instead of <tt>$fingerprint</tt> you can also specify a <a

1997) 
1998) href="https://secure.wikimedia.org/wikipedia/en/wiki/ISO_3166-1_alpha-2"
1999) >2

2000)     letter ISO3166 country code</a> in curly braces (for example <tt>{de}</tt>),

2001)     or an ip address pattern (for example 255.254.0.0/8).
2002)     Make sure there are no spaces between the commas and the

2003)     list items.

2004)     </p>
2005)     <p>

2006)     If you want to access a service directly through Tor's Socks
2007) interface

2008)     (eg. using ssh via connect.c), another option is to set up an

2009)     internal mapping in your configuration file using
2010) <tt>MapAddress</tt>.

2011)     See the manual page for details.
2012)     </p>

2013) 

2014)     <hr>

2015) 

2016) <a id="FirewallPorts"></a>

2017) <h3><a class="anchor" href="#FirewallPorts">My firewall only allows a
2018) few outgoing ports.</a></h3>

2019) 
2020) <p>
2021) If your firewall works by blocking ports, then you can tell Tor to only

2022) use the ports that your firewall permits by adding "FascistFirewall 1"
2023) to

2024) your <a href="<page docs/faq>#torrc">torrc

2025) configuration file</a>, or by clicking "My firewall only lets me connect
2026) to certain ports" in Vidalia's Network Settings window.
2027) </p>
2028) 
2029) <p>
2030) By default, when you set this Tor assumes that your firewall allows only
2031) port 80 and port 443 (HTTP and HTTPS respectively). You can select a
2032) different set of ports with the FirewallPorts torrc option.
2033) </p>
2034) 
2035) <p>
2036) If you want to be more fine-grained with your controls, you can also
2037) use the ReachableAddresses config options, e.g.:
2038) </p>
2039) 
2040) <pre>
2041)   ReachableDirAddresses *:80
2042)   ReachableORAddresses *:443
2043) </pre>
2044) 
2045) <hr>

2046) 

2047)     <a id="DefaultExitPorts"></a>

2048)     <h3><a class="anchor" href="#DefaultExitPorts">Is there a list of default exit

2049)     ports?</a></h3>

2050)     <p>

2051) The default open ports are listed below but keep in mind that, any port or
2052) ports can be opened by the relay operator by configuring it in torrc or
2053) modifying the source code. But the default according to src/or/policies.c
2054) from the source code release tor-0.2.4.16-rc is:

2055)     </p>
2056)     <pre>
2057)   reject 0.0.0.0/8
2058)   reject 169.254.0.0/16
2059)   reject 127.0.0.0/8
2060)   reject 192.168.0.0/16
2061)   reject 10.0.0.0/8
2062)   reject 172.16.0.0/12
2063)   reject *:25
2064)   reject *:119
2065)   reject *:135-139
2066)   reject *:445
2067)   reject *:563
2068)   reject *:1214
2069)   reject *:4661-4666
2070)   reject *:6346-6429
2071)   reject *:6699
2072)   reject *:6881-6999
2073)   accept *:*
2074)     </pre>
2075)     <p>

2076)     A relay will block access to its own IP address, as well local network
2077)     IP addresses. A relay always blocks itself by default. This prevents
2078)     Tor users from accidentally accessing any of the exit operator's local
2079)     services.

2080)     </p>
2081) 
2082)     <hr>
2083) 

2084)     <a id="WarningsAboutSOCKSandDNSInformationLeaks"></a>

2085)     <h3><a class="anchor" href="#WarningsAboutSOCKSandDNSInformationLeaks">I
2086)     keep seeing these warnings about SOCKS and DNS information leaks.

2087)     Should I worry?</a></h3>
2088)     <p>

2089)     The warning is:

2090)     </p>
2091)     <p>

2092)     Your application (using socks5 on port %d) is giving Tor only an IP
2093)     address. Applications that do DNS resolves themselves may leak
2094)     information. Consider using Socks4A (e.g. via Polipo or socat) instead.

2095)     </p>
2096)     <p>

2097)     If you are running Tor to get anonymity, and you are worried about an
2098)     attacker who is even slightly clever, then yes, you should worry. Here's why.

2099)     </p>
2100)     <p>

2101)     <b>The Problem.</b> When your applications connect to servers on the
2102)     Internet, they need to resolve hostnames that you can read (like
2103)     www.torproject.org) into IP addresses that the Internet can use (like
2104)     209.237.230.66). To do this, your application sends a request to a DNS
2105)     server, telling it the hostname it wants to resolve. The DNS server
2106)     replies by telling your application the IP address.

2107)     </p>
2108)     <p>

2109)     Clearly, this is a bad idea if you plan to connect to the remote host
2110)     anonymously: when your application sends the request to the DNS server,
2111)     the DNS server (and anybody else who might be watching) can see what
2112)     hostname you are asking for. Even if your application then uses Tor to
2113)     connect to the IP anonymously, it will be pretty obvious that the user
2114)     making the anonymous connection is probably the same person who made
2115)     the DNS request.

2116)     </p>
2117)     <p>