1 // Copyright (c) The Tor Project, Inc.
2 // See LICENSE for licensing information
3 // This is an asciidoc file used to generate the manpage/html reference.
4 // Learn asciidoc on http://www.methods.co.nz/asciidoc/userguide.html
6 :man manual: Tor Manual
12 tor - The second-generation onion router
17 **tor** [__OPTION__ __value__]...
21 Tor is a connection-oriented anonymizing communication
22 service. Users choose a source-routed path through a set of nodes, and
23 negotiate a "virtual circuit" through the network, in which each node
24 knows its predecessor and successor, but no others. Traffic flowing down
25 the circuit is unwrapped by a symmetric key at each node, which reveals
26 the downstream node. +
28 Basically, Tor provides a distributed network of servers or relays ("onion routers").
29 Users bounce their TCP streams -- web traffic, ftp, ssh, etc. -- around the
30 network, and recipients, observers, and even the relays themselves have
31 difficulty tracking the source of the stream.
33 By default, **tor** will only act as a client only. To help the network
34 by providing bandwidth as a relay, change the **ORPort** configuration
35 option -- see below. Please also consult the documentation on the Tor
40 [[opt-h]] **-h**, **-help**::
41 Display a short help message and exit.
43 [[opt-f]] **-f** __FILE__::
44 Specify a new configuration file to contain further Tor configuration
45 options. (Default: @CONFDIR@/torrc, or $HOME/.torrc if that file is not
48 [[opt-allow-missing-torrc]] **--allow-missing-torrc**::
49 Do not require that configuration file specified by **-f** exist if
50 default torrc can be accessed.
52 [[opt-defaults-torrc]] **--defaults-torrc** __FILE__::
53 Specify a file in which to find default values for Tor options. The
54 contents of this file are overridden by those in the regular
55 configuration file, and by those on the command line. (Default:
56 @CONFDIR@/torrc-defaults.)
58 [[opt-ignore-missing-torrc]] **--ignore-missing-torrc**::
59 Specifies that Tor should treat a missing torrc file as though it
60 were empty. Ordinarily, Tor does this for missing default torrc files,
61 but not for those specified on the command line.
63 [[opt-hash-password]] **--hash-password** __PASSWORD__::
64 Generates a hashed password for control port access.
66 [[opt-list-fingerprint]] **--list-fingerprint**::
67 Generate your keys and output your nickname and fingerprint.
69 [[opt-verify-config]] **--verify-config**::
70 Verify the configuration file is valid.
72 [[opt-serviceinstall]] **--service install** [**--options** __command-line options__]::
73 Install an instance of Tor as a Windows service, with the provided
74 command-line options. Current instructions can be found at
75 https://trac.torproject.org/projects/tor/wiki/doc/TorFAQ#HowdoIrunmyTorrelayasanNTservice
77 [[opt-service]] **--service** **remove**|**start**|**stop**::
78 Remove, start, or stop a configured Tor Windows service.
80 [[opt-nt-service]] **--nt-service**::
81 Used internally to implement a Windows service.
83 [[opt-list-torrc-options]] **--list-torrc-options**::
84 List all valid options.
86 [[opt-version]] **--version**::
87 Display Tor version and exit.
89 [[opt-quiet]] **--quiet**|**--hush**::
90 Override the default console log. By default, Tor starts out logging
91 messages at level "notice" and higher to the console. It stops doing so
92 after it parses its configuration, if the configuration tells it to log
93 anywhere else. You can override this behavior with the **--hush** option,
94 which tells Tor to only send warnings and errors to the console, or with
95 the **--quiet** option, which tells Tor not to log to the console at all.
97 Other options can be specified on the command-line in the format "--option
98 value", in the format "option value", or in a configuration file. For
99 instance, you can tell Tor to start listening for SOCKS connections on port
100 9999 by passing --SOCKSPort 9999 or SOCKSPort 9999 to it on the command line,
101 or by putting "SOCKSPort 9999" in the configuration file. You will need to
102 quote options with spaces in them: if you want Tor to log all debugging
103 messages to debug.log, you will probably need to say --Log 'debug file
106 Options on the command line override those in configuration files. See the
107 next section for more information.
109 THE CONFIGURATION FILE FORMAT
110 -----------------------------
112 All configuration options in a configuration are written on a single line by
113 default. They take the form of an option name and a value, or an option name
114 and a quoted value (option value or option "value"). Anything after a #
115 character is treated as a comment. Options are
116 case-insensitive. C-style escaped characters are allowed inside quoted
117 values. To split one configuration entry into multiple lines, use a single
118 backslash character (\) before the end of the line. Comments can be used in
119 such multiline entries, but they must start at the beginning of a line.
121 By default, an option on the command line overrides an option found in the
122 configuration file, and an option in a configuration file overrides one in
125 This rule is simple for options that take a single value, but it can become
126 complicated for options that are allowed to occur more than once: if you
127 specify four SOCKSPorts in your configuration file, and one more SOCKSPort on
128 the command line, the option on the command line will replace __all__ of the
129 SOCKSPorts in the configuration file. If this isn't what you want, prefix
130 the option name with a plus sign, and it will be appended to the previous set
133 Alternatively, you might want to remove every instance of an option in the
134 configuration file, and not replace it at all: you might want to say on the
135 command line that you want no SOCKSPorts at all. To do that, prefix the
136 option name with a forward slash.
141 [[BandwidthRate]] **BandwidthRate** __N__ **bytes**|**KBytes**|**MBytes**|**GBytes**|**KBits**|**MBits**|**GBits**::
142 A token bucket limits the average incoming bandwidth usage on this node to
143 the specified number of bytes per second, and the average outgoing
144 bandwidth usage to that same value. If you want to run a relay in the
145 public network, this needs to be _at the very least_ 30 KBytes (that is,
146 30720 bytes). (Default: 1 GByte) +
148 With this option, and in other options that take arguments in bytes,
149 KBytes, and so on, other formats are also supported. Notably, "KBytes" can
150 also be written as "kilobytes" or "kb"; "MBytes" can be written as
151 "megabytes" or "MB"; "kbits" can be written as "kilobits"; and so forth.
152 Tor also accepts "byte" and "bit" in the singular.
153 The prefixes "tera" and "T" are also recognized.
154 If no units are given, we default to bytes.
155 To avoid confusion, we recommend writing "bytes" or "bits" explicitly,
156 since it's easy to forget that "B" means bytes, not bits.
158 [[BandwidthBurst]] **BandwidthBurst** __N__ **bytes**|**KBytes**|**MBytes**|**GBytes**|**KBits**|**MBits**|**GBits**::
159 Limit the maximum token bucket size (also known as the burst) to the given
160 number of bytes in each direction. (Default: 1 GByte)
162 [[MaxAdvertisedBandwidth]] **MaxAdvertisedBandwidth** __N__ **bytes**|**KBytes**|**MBytes**|**GBytes**|**KBits**|**MBits**|**GBits**::
163 If set, we will not advertise more than this amount of bandwidth for our
164 BandwidthRate. Server operators who want to reduce the number of clients
165 who ask to build circuits through them (since this is proportional to
166 advertised bandwidth rate) can thus reduce the CPU demands on their server
167 without impacting network performance.
169 [[RelayBandwidthRate]] **RelayBandwidthRate** __N__ **bytes**|**KBytes**|**MBytes**|**GBytes**|**KBits**|**MBits**|**GBits**::
170 If not 0, a separate token bucket limits the average incoming bandwidth
171 usage for \_relayed traffic_ on this node to the specified number of bytes
172 per second, and the average outgoing bandwidth usage to that same value.
173 Relayed traffic currently is calculated to include answers to directory
174 requests, but that may change in future versions. (Default: 0)
176 [[RelayBandwidthBurst]] **RelayBandwidthBurst** __N__ **bytes**|**KBytes**|**MBytes**|**GBytes**|**KBits**|**MBits**|**GBits**::
177 If not 0, limit the maximum token bucket size (also known as the burst) for
178 \_relayed traffic_ to the given number of bytes in each direction.
181 [[PerConnBWRate]] **PerConnBWRate** __N__ **bytes**|**KBytes**|**MBytes**|**GBytes**|**KBits**|**MBits**|**GBits**::
182 If set, do separate rate limiting for each connection from a non-relay.
183 You should never need to change this value, since a network-wide value is
184 published in the consensus and your relay will use that value. (Default: 0)
186 [[PerConnBWBurst]] **PerConnBWBurst** __N__ **bytes**|**KBytes**|**MBytes**|**GBytes**|**KBits**|**MBits**|**GBits**::
187 If set, do separate rate limiting for each connection from a non-relay.
188 You should never need to change this value, since a network-wide value is
189 published in the consensus and your relay will use that value. (Default: 0)
191 [[ClientTransportPlugin]] **ClientTransportPlugin** __transport__ socks4|socks5 __IP__:__PORT__::
192 **ClientTransportPlugin** __transport__ exec __path-to-binary__ [options]::
193 In its first form, when set along with a corresponding Bridge line, the Tor
194 client forwards its traffic to a SOCKS-speaking proxy on "IP:PORT". It's the
195 duty of that proxy to properly forward the traffic to the bridge. +
197 In its second form, when set along with a corresponding Bridge line, the Tor
198 client launches the pluggable transport proxy executable in
199 __path-to-binary__ using __options__ as its command-line options, and
200 forwards its traffic to it. It's the duty of that proxy to properly forward
201 the traffic to the bridge.
203 [[ServerTransportPlugin]] **ServerTransportPlugin** __transport__ exec __path-to-binary__ [options]::
204 The Tor relay launches the pluggable transport proxy in __path-to-binary__
205 using __options__ as its command-line options, and expects to receive
206 proxied client traffic from it.
208 [[ServerTransportListenAddr]] **ServerTransportListenAddr** __transport__ __IP__:__PORT__::
209 When this option is set, Tor will suggest __IP__:__PORT__ as the
210 listening address of any pluggable transport proxy that tries to
211 launch __transport__.
213 [[ServerTransportOptions]] **ServerTransportOptions** __transport__ __k=v__ __k=v__ ...::
214 When this option is set, Tor will pass the __k=v__ parameters to
215 any pluggable transport proxy that tries to launch __transport__. +
216 (Example: ServerTransportOptions obfs45 shared-secret=bridgepasswd cache=/var/lib/tor/cache)
218 [[ExtORPort]] **ExtORPort** \['address':]__port__|**auto**
219 Open this port to listen for Extended ORPort connections from your
220 pluggable transports.
222 [[ExtORPortCookieAuthFile]] **ExtORPortCookieAuthFile** __Path__::
223 If set, this option overrides the default location and file name
224 for the Extended ORPort's cookie file -- the cookie file is needed
225 for pluggable transports to communicate through the Extended ORPort.
227 [[ExtORPortCookieAuthFileGroupReadable]] **ExtORPortCookieAuthFileGroupReadable** **0**|**1**::
228 If this option is set to 0, don't allow the filesystem group to read the
229 Extended OR Port cookie file. If the option is set to 1, make the cookie
230 file readable by the default GID. [Making the file readable by other
231 groups is not yet implemented; let us know if you need this for some
232 reason.] (Default: 0)
234 [[ConnLimit]] **ConnLimit** __NUM__::
235 The minimum number of file descriptors that must be available to the Tor
236 process before it will start. Tor will ask the OS for as many file
237 descriptors as the OS will allow (you can find this by "ulimit -H -n").
238 If this number is less than ConnLimit, then Tor will refuse to start. +
240 You probably don't need to adjust this. It has no effect on Windows
241 since that platform lacks getrlimit(). (Default: 1000)
243 [[DisableNetwork]] **DisableNetwork** **0**|**1**::
244 When this option is set, we don't listen for or accept any connections
245 other than controller connections, and we close (and don't reattempt)
247 connections. Controllers sometimes use this option to avoid using
248 the network until Tor is fully configured. (Default: 0)
250 [[ConstrainedSockets]] **ConstrainedSockets** **0**|**1**::
251 If set, Tor will tell the kernel to attempt to shrink the buffers for all
252 sockets to the size specified in **ConstrainedSockSize**. This is useful for
253 virtual servers and other environments where system level TCP buffers may
254 be limited. If you're on a virtual server, and you encounter the "Error
255 creating network socket: No buffer space available" message, you are
256 likely experiencing this problem. +
258 The preferred solution is to have the admin increase the buffer pool for
259 the host itself via /proc/sys/net/ipv4/tcp_mem or equivalent facility;
260 this configuration option is a second-resort. +
262 The DirPort option should also not be used if TCP buffers are scarce. The
263 cached directory requests consume additional sockets which exacerbates
266 You should **not** enable this feature unless you encounter the "no buffer
267 space available" issue. Reducing the TCP buffers affects window size for
268 the TCP stream and will reduce throughput in proportion to round trip
269 time on long paths. (Default: 0)
271 [[ConstrainedSockSize]] **ConstrainedSockSize** __N__ **bytes**|**KBytes**::
272 When **ConstrainedSockets** is enabled the receive and transmit buffers for
273 all sockets will be set to this limit. Must be a value between 2048 and
274 262144, in 1024 byte increments. Default of 8192 is recommended.
276 [[ControlPort]] **ControlPort** __PORT__|**auto**::
277 If set, Tor will accept connections on this port and allow those
278 connections to control the Tor process using the Tor Control Protocol
279 (described in control-spec.txt). Note: unless you also specify one or
280 more of **HashedControlPassword** or **CookieAuthentication**,
281 setting this option will cause Tor to allow any process on the local
282 host to control it. (Setting both authentication methods means either
283 method is sufficient to authenticate to Tor.) This
284 option is required for many Tor controllers; most use the value of 9051.
285 Set it to "auto" to have Tor pick a port for you. (Default: 0)
287 [[ControlListenAddress]] **ControlListenAddress** __IP__[:__PORT__]::
288 Bind the controller listener to this address. If you specify a port, bind
289 to this port rather than the one specified in ControlPort. We strongly
290 recommend that you leave this alone unless you know what you're doing,
291 since giving attackers access to your control listener is really
292 dangerous. This directive can be specified multiple
293 times to bind to multiple addresses/ports. (Default: 127.0.0.1)
295 [[ControlSocket]] **ControlSocket** __Path__::
296 Like ControlPort, but listens on a Unix domain socket, rather than a TCP
297 socket. (Unix and Unix-like systems only.)
299 [[ControlSocketsGroupWritable]] **ControlSocketsGroupWritable** **0**|**1**::
300 If this option is set to 0, don't allow the filesystem group to read and
301 write unix sockets (e.g. ControlSocket). If the option is set to 1, make
302 the control socket readable and writable by the default GID. (Default: 0)
304 [[HashedControlPassword]] **HashedControlPassword** __hashed_password__::
305 Allow connections on the control port if they present
306 the password whose one-way hash is __hashed_password__. You
307 can compute the hash of a password by running "tor --hash-password
308 __password__". You can provide several acceptable passwords by using more
309 than one HashedControlPassword line.
311 [[CookieAuthentication]] **CookieAuthentication** **0**|**1**::
312 If this option is set to 1, allow connections on the control port
313 when the connecting process knows the contents of a file named
314 "control_auth_cookie", which Tor will create in its data directory. This
315 authentication method should only be used on systems with good filesystem
316 security. (Default: 0)
318 [[CookieAuthFile]] **CookieAuthFile** __Path__::
319 If set, this option overrides the default location and file name
320 for Tor's cookie file. (See CookieAuthentication above.)
322 [[CookieAuthFileGroupReadable]] **CookieAuthFileGroupReadable** **0**|**1**::
323 If this option is set to 0, don't allow the filesystem group to read the
324 cookie file. If the option is set to 1, make the cookie file readable by
325 the default GID. [Making the file readable by other groups is not yet
326 implemented; let us know if you need this for some reason.] (Default: 0)
328 [[ControlPortWriteToFile]] **ControlPortWriteToFile** __Path__::
329 If set, Tor writes the address and port of any control port it opens to
330 this address. Usable by controllers to learn the actual control port
331 when ControlPort is set to "auto".
333 [[ControlPortFileGroupReadable]] **ControlPortFileGroupReadable** **0**|**1**::
334 If this option is set to 0, don't allow the filesystem group to read the
335 control port file. If the option is set to 1, make the control port
336 file readable by the default GID. (Default: 0)
338 [[DataDirectory]] **DataDirectory** __DIR__::
339 Store working data in DIR (Default: @LOCALSTATEDIR@/lib/tor)
341 [[FallbackDir]] **FallbackDir** __address__:__port__ orport=__port__ id=__fingerprint__ [weight=__num__]::
342 When we're unable to connect to any directory cache for directory info
343 (usually because we don't know about any yet) we try a FallbackDir.
344 By default, the directory authorities are also FallbackDirs.
346 [[DirAuthority]] **DirAuthority** [__nickname__] [**flags**] __address__:__port__ __fingerprint__::
347 Use a nonstandard authoritative directory server at the provided address
348 and port, with the specified key fingerprint. This option can be repeated
349 many times, for multiple authoritative directory servers. Flags are
350 separated by spaces, and determine what kind of an authority this directory
351 is. By default, an authority is not authoritative for any directory style
352 or version unless an appropriate flag is given.
353 Tor will use this authority as a bridge authoritative directory if the
354 "bridge" flag is set. If a flag "orport=**port**" is given, Tor will use the
355 given port when opening encrypted tunnels to the dirserver. If a flag
356 "weight=**num**" is given, then the directory server is chosen randomly
357 with probability proportional to that weight (default 1.0). Lastly, if a
358 flag "v3ident=**fp**" is given, the dirserver is a v3 directory authority
359 whose v3 long-term signing key has the fingerprint **fp**. +
361 If no **DirAuthority** line is given, Tor will use the default directory
362 authorities. NOTE: this option is intended for setting up a private Tor
363 network with its own directory authorities. If you use it, you will be
364 distinguishable from other users, because you won't believe the same
367 [[DirAuthorityFallbackRate]] **DirAuthorityFallbackRate** __NUM__::
368 When configured to use both directory authorities and fallback
369 directories, the directory authorities also work as fallbacks. They are
370 chosen with their regular weights, multiplied by this number, which
371 should be 1.0 or less. (Default: 1.0)
373 [[DynamicDHGroups]] **DynamicDHGroups** **0**|**1**::
374 If this option is set to 1, when running as a server, generate our
375 own Diffie-Hellman group instead of using the one from Apache's mod_ssl.
376 This option may help circumvent censorship based on static
377 Diffie-Hellman parameters. (Default: 0)
379 [[AlternateDirAuthority]] **AlternateDirAuthority** [__nickname__] [**flags**] __address__:__port__ __fingerprint__ +
381 [[AlternateBridgeAuthority]] **AlternateBridgeAuthority** [__nickname__] [**flags**] __address__:__port__ __ fingerprint__::
382 These options behave as DirAuthority, but they replace fewer of the
383 default directory authorities. Using
384 AlternateDirAuthority replaces the default Tor directory authorities, but
385 leaves the default bridge authorities in
387 AlternateBridgeAuthority replaces the default bridge authority,
388 but leaves the directory authorities alone.
390 [[DisableAllSwap]] **DisableAllSwap** **0**|**1**::
391 If set to 1, Tor will attempt to lock all current and future memory pages,
392 so that memory cannot be paged out. Windows, OS X and Solaris are currently
393 not supported. We believe that this feature works on modern Gnu/Linux
394 distributions, and that it should work on *BSD systems (untested). This
395 option requires that you start your Tor as root, and you should use the
396 **User** option to properly reduce Tor's privileges. (Default: 0)
398 [[DisableDebuggerAttachment]] **DisableDebuggerAttachment** **0**|**1**::
399 If set to 1, Tor will attempt to prevent basic debugging attachment attempts
400 by other processes. This may also keep Tor from generating core files if
401 it crashes. It has no impact for users who wish to attach if they
402 have CAP_SYS_PTRACE or if they are root. We believe that this feature
403 works on modern Gnu/Linux distributions, and that it may also work on *BSD
404 systems (untested). Some modern Gnu/Linux systems such as Ubuntu have the
405 kernel.yama.ptrace_scope sysctl and by default enable it as an attempt to
406 limit the PTRACE scope for all user processes by default. This feature will
407 attempt to limit the PTRACE scope for Tor specifically - it will not attempt
408 to alter the system wide ptrace scope as it may not even exist. If you wish
409 to attach to Tor with a debugger such as gdb or strace you will want to set
410 this to 0 for the duration of your debugging. Normal users should leave it
411 on. Disabling this option while Tor is running is prohibited. (Default: 1)
413 [[FetchDirInfoEarly]] **FetchDirInfoEarly** **0**|**1**::
414 If set to 1, Tor will always fetch directory information like other
415 directory caches, even if you don't meet the normal criteria for fetching
416 early. Normal users should leave it off. (Default: 0)
418 [[FetchDirInfoExtraEarly]] **FetchDirInfoExtraEarly** **0**|**1**::
419 If set to 1, Tor will fetch directory information before other directory
420 caches. It will attempt to download directory information closer to the
421 start of the consensus period. Normal users should leave it off.
424 [[FetchHidServDescriptors]] **FetchHidServDescriptors** **0**|**1**::
425 If set to 0, Tor will never fetch any hidden service descriptors from the
426 rendezvous directories. This option is only useful if you're using a Tor
427 controller that handles hidden service fetches for you. (Default: 1)
429 [[FetchServerDescriptors]] **FetchServerDescriptors** **0**|**1**::
430 If set to 0, Tor will never fetch any network status summaries or server
431 descriptors from the directory servers. This option is only useful if
432 you're using a Tor controller that handles directory fetches for you.
435 [[FetchUselessDescriptors]] **FetchUselessDescriptors** **0**|**1**::
436 If set to 1, Tor will fetch every non-obsolete descriptor from the
437 authorities that it hears about. Otherwise, it will avoid fetching useless
438 descriptors, for example for routers that are not running. This option is
439 useful if you're using the contributed "exitlist" script to enumerate Tor
440 nodes that exit to certain addresses. (Default: 0)
442 [[HTTPProxy]] **HTTPProxy** __host__[:__port__]::
443 Tor will make all its directory requests through this host:port (or host:80
444 if port is not specified), rather than connecting directly to any directory
447 [[HTTPProxyAuthenticator]] **HTTPProxyAuthenticator** __username:password__::
448 If defined, Tor will use this username:password for Basic HTTP proxy
449 authentication, as in RFC 2617. This is currently the only form of HTTP
450 proxy authentication that Tor supports; feel free to submit a patch if you
451 want it to support others.
453 [[HTTPSProxy]] **HTTPSProxy** __host__[:__port__]::
454 Tor will make all its OR (SSL) connections through this host:port (or
455 host:443 if port is not specified), via HTTP CONNECT rather than connecting
456 directly to servers. You may want to set **FascistFirewall** to restrict
457 the set of ports you might try to connect to, if your HTTPS proxy only
458 allows connecting to certain ports.
460 [[HTTPSProxyAuthenticator]] **HTTPSProxyAuthenticator** __username:password__::
461 If defined, Tor will use this username:password for Basic HTTPS proxy
462 authentication, as in RFC 2617. This is currently the only form of HTTPS
463 proxy authentication that Tor supports; feel free to submit a patch if you
464 want it to support others.
466 [[Sandbox]] **Sandbox** **0**|**1**::
467 If set to 1, Tor will run securely through the use of a syscall sandbox.
468 Otherwise the sandbox will be disabled. The option is currently an
469 experimental feature. (Default: 0)
471 [[Socks4Proxy]] **Socks4Proxy** __host__[:__port__]::
472 Tor will make all OR connections through the SOCKS 4 proxy at host:port
473 (or host:1080 if port is not specified).
475 [[Socks5Proxy]] **Socks5Proxy** __host__[:__port__]::
476 Tor will make all OR connections through the SOCKS 5 proxy at host:port
477 (or host:1080 if port is not specified).
479 [[Socks5ProxyUsername]] **Socks5ProxyUsername** __username__ +
481 [[Socks5ProxyPassword]] **Socks5ProxyPassword** __password__::
482 If defined, authenticate to the SOCKS 5 server using username and password
483 in accordance to RFC 1929. Both username and password must be between 1 and
486 [[KeepalivePeriod]] **KeepalivePeriod** __NUM__::
487 To keep firewalls from expiring connections, send a padding keepalive cell
488 every NUM seconds on open connections that are in use. If the connection
489 has no open circuits, it will instead be closed after NUM seconds of
490 idleness. (Default: 5 minutes)
492 [[Log]] **Log** __minSeverity__[-__maxSeverity__] **stderr**|**stdout**|**syslog**::
493 Send all messages between __minSeverity__ and __maxSeverity__ to the standard
494 output stream, the standard error stream, or to the system log. (The
495 "syslog" value is only supported on Unix.) Recognized severity levels are
496 debug, info, notice, warn, and err. We advise using "notice" in most cases,
497 since anything more verbose may provide sensitive information to an
498 attacker who obtains the logs. If only one severity level is given, all
499 messages of that level or higher will be sent to the listed destination.
501 [[Log2]] **Log** __minSeverity__[-__maxSeverity__] **file** __FILENAME__::
502 As above, but send log messages to the listed filename. The
503 "Log" option may appear more than once in a configuration file.
504 Messages are sent to all the logs that match their severity
507 [[Log3]] **Log** **[**__domain__,...**]**__minSeverity__[-__maxSeverity__] ... **file** __FILENAME__ +
509 [[Log4]] **Log** **[**__domain__,...**]**__minSeverity__[-__maxSeverity__] ... **stderr**|**stdout**|**syslog**::
510 As above, but select messages by range of log severity __and__ by a
511 set of "logging domains". Each logging domain corresponds to an area of
512 functionality inside Tor. You can specify any number of severity ranges
513 for a single log statement, each of them prefixed by a comma-separated
514 list of logging domains. You can prefix a domain with $$~$$ to indicate
515 negation, and use * to indicate "all domains". If you specify a severity
516 range without a list of domains, it matches all domains. +
518 This is an advanced feature which is most useful for debugging one or two
519 of Tor's subsystems at a time. +
521 The currently recognized domains are: general, crypto, net, config, fs,
522 protocol, mm, http, app, control, circ, rend, bug, dir, dirserv, or, edge,
523 acct, hist, and handshake. Domain names are case-insensitive. +
525 For example, "`Log [handshake]debug [~net,~mm]info notice stdout`" sends
526 to stdout: all handshake messages of any severity, all info-and-higher
527 messages from domains other than networking and memory management, and all
528 messages of severity notice or higher.
530 [[LogMessageDomains]] **LogMessageDomains** **0**|**1**::
531 If 1, Tor includes message domains with each log message. Every log
532 message currently has at least one domain; most currently have exactly
533 one. This doesn't affect controller log messages. (Default: 0)
535 [[OutboundBindAddress]] **OutboundBindAddress** __IP__::
536 Make all outbound connections originate from the IP address specified. This
537 is only useful when you have multiple network interfaces, and you want all
538 of Tor's outgoing connections to use a single one. This option may
539 be used twice, once with an IPv4 address and once with an IPv6 address.
540 This setting will be ignored for connections to the loopback addresses
541 (127.0.0.0/8 and ::1).
543 [[PidFile]] **PidFile** __FILE__::
544 On startup, write our PID to FILE. On clean shutdown, remove
547 [[ProtocolWarnings]] **ProtocolWarnings** **0**|**1**::
548 If 1, Tor will log with severity \'warn' various cases of other parties not
549 following the Tor specification. Otherwise, they are logged with severity
550 \'info'. (Default: 0)
552 [[PredictedPortsRelevanceTime]] **PredictedPortsRelevanceTime** __NUM__::
553 Set how long, after the client has mad an anonymized connection to a
554 given port, we will try to make sure that we build circuits to
555 exits that support that port. The maximum value for this option is 1
556 hour. (Default: 1 hour)
558 [[RunAsDaemon]] **RunAsDaemon** **0**|**1**::
559 If 1, Tor forks and daemonizes to the background. This option has no effect
560 on Windows; instead you should use the --service command-line option.
563 [[LogTimeGranularity]] **LogTimeGranularity** __NUM__::
564 Set the resolution of timestamps in Tor's logs to NUM milliseconds.
565 NUM must be positive and either a divisor or a multiple of 1 second.
566 Note that this option only controls the granularity written by Tor to
567 a file or console log. Tor does not (for example) "batch up" log
568 messages to affect times logged by a controller, times attached to
569 syslog messages, or the mtime fields on log files. (Default: 1 second)
571 [[SafeLogging]] **SafeLogging** **0**|**1**|**relay**::
572 Tor can scrub potentially sensitive strings from log messages (e.g.
573 addresses) by replacing them with the string [scrubbed]. This way logs can
574 still be useful, but they don't leave behind personally identifying
575 information about what sites a user might have visited. +
577 If this option is set to 0, Tor will not perform any scrubbing, if it is
578 set to 1, all potentially sensitive strings are replaced. If it is set to
579 relay, all log messages generated when acting as a relay are sanitized, but
580 all messages generated when acting as a client are not. (Default: 1)
582 [[User]] **User** __UID__::
583 On startup, setuid to this user and setgid to their primary group.
585 [[HardwareAccel]] **HardwareAccel** **0**|**1**::
586 If non-zero, try to use built-in (static) crypto hardware acceleration when
587 available. (Default: 0)
589 [[AccelName]] **AccelName** __NAME__::
590 When using OpenSSL hardware crypto acceleration attempt to load the dynamic
591 engine of this name. This must be used for any dynamic hardware engine.
592 Names can be verified with the openssl engine command.
594 [[AccelDir]] **AccelDir** __DIR__::
595 Specify this option if using dynamic hardware acceleration and the engine
596 implementation library resides somewhere other than the OpenSSL default.
598 [[AvoidDiskWrites]] **AvoidDiskWrites** **0**|**1**::
599 If non-zero, try to write to disk less frequently than we would otherwise.
600 This is useful when running on flash memory or other media that support
601 only a limited number of writes. (Default: 0)
603 [[CircuitPriorityHalflife]] **CircuitPriorityHalflife** __NUM1__::
604 If this value is set, we override the default algorithm for choosing which
605 circuit's cell to deliver or relay next. When the value is 0, we
606 round-robin between the active circuits on a connection, delivering one
607 cell from each in turn. When the value is positive, we prefer delivering
608 cells from whichever connection has the lowest weighted cell count, where
609 cells are weighted exponentially according to the supplied
610 CircuitPriorityHalflife value (in seconds). If this option is not set at
611 all, we use the behavior recommended in the current consensus
612 networkstatus. This is an advanced option; you generally shouldn't have
613 to mess with it. (Default: not set)
615 [[DisableIOCP]] **DisableIOCP** **0**|**1**::
616 If Tor was built to use the Libevent's "bufferevents" networking code
617 and you're running on Windows, setting this option to 1 will tell Libevent
618 not to use the Windows IOCP networking API. (Default: 1)
620 [[UserspaceIOCPBuffers]] **UserspaceIOCPBuffers** **0**|**1**::
621 If IOCP is enabled (see DisableIOCP above), setting this option to 1
622 will tell Tor to disable kernel-space TCP buffers, in order to avoid
623 needless copy operations and try not to run out of non-paged RAM.
624 This feature is experimental; don't use it yet unless you're eager to
625 help tracking down bugs. (Default: 0)
627 [[UseFilteringSSLBufferevents]] **UseFilteringSSLBufferevents** **0**|**1**::
628 Tells Tor to do its SSL communication using a chain of
629 bufferevents: one for SSL and one for networking. This option has no
630 effect if bufferevents are disabled (in which case it can't turn on), or
631 if IOCP bufferevents are enabled (in which case it can't turn off). This
632 option is useful for debugging only; most users shouldn't touch it.
635 [[CountPrivateBandwidth]] **CountPrivateBandwidth** **0**|**1**::
636 If this option is set, then Tor's rate-limiting applies not only to
637 remote connections, but also to connections to private addresses like
638 127.0.0.1 or 10.0.0.1. This is mostly useful for debugging
639 rate-limiting. (Default: 0)
644 The following options are useful only for clients (that is, if
645 **SocksPort**, **TransPort**, **DNSPort**, or **NATDPort** is non-zero):
647 [[AllowInvalidNodes]] **AllowInvalidNodes** **entry**|**exit**|**middle**|**introduction**|**rendezvous**|**...**::
648 If some Tor servers are obviously not working right, the directory
649 authorities can manually mark them as invalid, meaning that it's not
650 recommended you use them for entry or exit positions in your circuits. You
651 can opt to use them in some circuit positions, though. The default is
652 "middle,rendezvous", and other choices are not advised.
654 [[ExcludeSingleHopRelays]] **ExcludeSingleHopRelays** **0**|**1**::
655 This option controls whether circuits built by Tor will include relays with
656 the AllowSingleHopExits flag set to true. If ExcludeSingleHopRelays is set
657 to 0, these relays will be included. Note that these relays might be at
658 higher risk of being seized or observed, so they are not normally
659 included. Also note that relatively few clients turn off this option,
660 so using these relays might make your client stand out.
663 [[Bridge]] **Bridge** [__transport__] __IP__:__ORPort__ [__fingerprint__]::
664 When set along with UseBridges, instructs Tor to use the relay at
665 "IP:ORPort" as a "bridge" relaying into the Tor network. If "fingerprint"
666 is provided (using the same format as for DirAuthority), we will verify that
667 the relay running at that location has the right fingerprint. We also use
668 fingerprint to look up the bridge descriptor at the bridge authority, if
669 it's provided and if UpdateBridgesFromAuthority is set too. +
671 If "transport" is provided, and matches to a ClientTransportPlugin
672 line, we use that pluggable transports proxy to transfer data to
675 [[LearnCircuitBuildTimeout]] **LearnCircuitBuildTimeout** **0**|**1**::
676 If 0, CircuitBuildTimeout adaptive learning is disabled. (Default: 1)
678 [[CircuitBuildTimeout]] **CircuitBuildTimeout** __NUM__::
680 Try for at most NUM seconds when building circuits. If the circuit isn't
681 open in that time, give up on it. If LearnCircuitBuildTimeout is 1, this
682 value serves as the initial value to use before a timeout is learned. If
683 LearnCircuitBuildTimeout is 0, this value is the only value used.
684 (Default: 60 seconds)
686 [[CircuitIdleTimeout]] **CircuitIdleTimeout** __NUM__::
687 If we have kept a clean (never used) circuit around for NUM seconds, then
688 close it. This way when the Tor client is entirely idle, it can expire all
689 of its circuits, and then expire its TLS connections. Also, if we end up
690 making a circuit that is not useful for exiting any of the requests we're
691 receiving, it won't forever take up a slot in the circuit list. (Default: 1
694 [[CircuitStreamTimeout]] **CircuitStreamTimeout** __NUM__::
695 If non-zero, this option overrides our internal timeout schedule for how
696 many seconds until we detach a stream from a circuit and try a new circuit.
697 If your network is particularly slow, you might want to set this to a
698 number like 60. (Default: 0)
700 [[ClientOnly]] **ClientOnly** **0**|**1**::
701 If set to 1, Tor will not run as a relay or serve
702 directory requests, even if the ORPort, ExtORPort, or DirPort options are
703 set. (This config option is
704 mostly unnecessary: we added it back when we were considering having
705 Tor clients auto-promote themselves to being relays if they were stable
706 and fast enough. The current behavior is simply that Tor is a client
707 unless ORPort, ExtORPort, or DirPort are configured.) (Default: 0)
709 [[ExcludeNodes]] **ExcludeNodes** __node__,__node__,__...__::
710 A list of identity fingerprints, nicknames, country codes and address
711 patterns of nodes to avoid when building a circuit.
713 ExcludeNodes SlowServer, ABCD1234CDEF5678ABCD1234CDEF5678ABCD1234, \{cc}, 255.254.0.0/8) +
715 By default, this option is treated as a preference that Tor is allowed
716 to override in order to keep working.
717 For example, if you try to connect to a hidden service,
718 but you have excluded all of the hidden service's introduction points,
719 Tor will connect to one of them anyway. If you do not want this
720 behavior, set the StrictNodes option (documented below). +
722 Note also that if you are a relay, this (and the other node selection
723 options below) only affects your own circuits that Tor builds for you.
724 Clients can still build circuits through you to any node. Controllers
725 can tell Tor to build circuits through any node. +
727 Country codes are case-insensitive. The code "\{??}" refers to nodes whose
728 country can't be identified. No country code, including \{??}, works if
729 no GeoIPFile can be loaded. See also the GeoIPExcludeUnknown option below.
732 [[ExcludeExitNodes]] **ExcludeExitNodes** __node__,__node__,__...__::
733 A list of identity fingerprints, nicknames, country codes and address
734 patterns of nodes to never use when picking an exit node---that is, a
735 node that delivers traffic for you outside the Tor network. Note that any
736 node listed in ExcludeNodes is automatically considered to be part of this
737 list too. See also the caveats on the "ExitNodes" option below.
739 [[GeoIPExcludeUnknown]] **GeoIPExcludeUnknown** **0**|**1**|**auto**::
740 If this option is set to 'auto', then whenever any country code is set in
741 ExcludeNodes or ExcludeExitNodes, all nodes with unknown country (\{??} and
742 possibly \{A1}) are treated as excluded as well. If this option is set to
743 '1', then all unknown countries are treated as excluded in ExcludeNodes
744 and ExcludeExitNodes. This option has no effect when a GeoIP file isn't
745 configured or can't be found. (Default: auto)
747 [[ExitNodes]] **ExitNodes** __node__,__node__,__...__::
748 A list of identity fingerprints, nicknames, country codes and address
749 patterns of nodes to use as exit node---that is, a
750 node that delivers traffic for you outside the Tor network. +
752 Note that if you list too few nodes here, or if you exclude too many exit
753 nodes with ExcludeExitNodes, you can degrade functionality. For example,
754 if none of the exits you list allows traffic on port 80 or 443, you won't
755 be able to browse the web. +
757 Note also that not every circuit is used to deliver traffic outside of
758 the Tor network. It is normal to see non-exit circuits (such as those
759 used to connect to hidden services, those that do directory fetches,
760 those used for relay reachability self-tests, and so on) that end
761 at a non-exit node. To
762 keep a node from being used entirely, see ExcludeNodes and StrictNodes. +
764 The ExcludeNodes option overrides this option: any node listed in both
765 ExitNodes and ExcludeNodes is treated as excluded. +
767 The .exit address notation, if enabled via AllowDotExit, overrides
770 [[EntryNodes]] **EntryNodes** __node__,__node__,__...__::
771 A list of identity fingerprints, nicknames, and country codes of nodes
772 to use for the first hop in your normal circuits.
773 Normal circuits include all
774 circuits except for direct connections to directory servers. The Bridge
775 option overrides this option; if you have configured bridges and
776 UseBridges is 1, the Bridges are used as your entry nodes. +
778 The ExcludeNodes option overrides this option: any node listed in both
779 EntryNodes and ExcludeNodes is treated as excluded.
781 [[StrictNodes]] **StrictNodes** **0**|**1**::
782 If StrictNodes is set to 1, Tor will treat the ExcludeNodes option as a
783 requirement to follow for all the circuits you generate, even if doing so
784 will break functionality for you. If StrictNodes is set to 0, Tor will
785 still try to avoid nodes in the ExcludeNodes list, but it will err on the
786 side of avoiding unexpected errors. Specifically, StrictNodes 0 tells
787 Tor that it is okay to use an excluded node when it is *necessary* to
788 perform relay reachability self-tests, connect to
789 a hidden service, provide a hidden service to a client, fulfill a .exit
790 request, upload directory information, or download directory information.
793 [[FascistFirewall]] **FascistFirewall** **0**|**1**::
794 If 1, Tor will only create outgoing connections to ORs running on ports
795 that your firewall allows (defaults to 80 and 443; see **FirewallPorts**).
796 This will allow you to run Tor as a client behind a firewall with
797 restrictive policies, but will not allow you to run as a server behind such
798 a firewall. If you prefer more fine-grained control, use
799 ReachableAddresses instead.
801 [[FirewallPorts]] **FirewallPorts** __PORTS__::
802 A list of ports that your firewall allows you to connect to. Only used when
803 **FascistFirewall** is set. This option is deprecated; use ReachableAddresses
804 instead. (Default: 80, 443)
806 [[ReachableAddresses]] **ReachableAddresses** __ADDR__[/__MASK__][:__PORT__]...::
807 A comma-separated list of IP addresses and ports that your firewall allows
808 you to connect to. The format is as for the addresses in ExitPolicy, except
809 that "accept" is understood unless "reject" is explicitly provided. For
810 example, \'ReachableAddresses 99.0.0.0/8, reject 18.0.0.0/8:80, accept
811 \*:80' means that your firewall allows connections to everything inside net
812 99, rejects port 80 connections to net 18, and accepts connections to port
813 80 otherwise. (Default: \'accept \*:*'.)
815 [[ReachableDirAddresses]] **ReachableDirAddresses** __ADDR__[/__MASK__][:__PORT__]...::
816 Like **ReachableAddresses**, a list of addresses and ports. Tor will obey
817 these restrictions when fetching directory information, using standard HTTP
818 GET requests. If not set explicitly then the value of
819 **ReachableAddresses** is used. If **HTTPProxy** is set then these
820 connections will go through that proxy.
822 [[ReachableORAddresses]] **ReachableORAddresses** __ADDR__[/__MASK__][:__PORT__]...::
823 Like **ReachableAddresses**, a list of addresses and ports. Tor will obey
824 these restrictions when connecting to Onion Routers, using TLS/SSL. If not
825 set explicitly then the value of **ReachableAddresses** is used. If
826 **HTTPSProxy** is set then these connections will go through that proxy. +
828 The separation between **ReachableORAddresses** and
829 **ReachableDirAddresses** is only interesting when you are connecting
830 through proxies (see **HTTPProxy** and **HTTPSProxy**). Most proxies limit
831 TLS connections (which Tor uses to connect to Onion Routers) to port 443,
832 and some limit HTTP GET requests (which Tor uses for fetching directory
833 information) to port 80.
835 [[HidServAuth]] **HidServAuth** __onion-address__ __auth-cookie__ [__service-name__]::
836 Client authorization for a hidden service. Valid onion addresses contain 16
837 characters in a-z2-7 plus ".onion", and valid auth cookies contain 22
838 characters in A-Za-z0-9+/. The service name is only used for internal
839 purposes, e.g., for Tor controllers. This option may be used multiple times
840 for different hidden services. If a hidden service uses authorization and
841 this option is not set, the hidden service is not accessible. Hidden
842 services can be configured to require authorization using the
843 **HiddenServiceAuthorizeClient** option.
845 [[CloseHSClientCircuitsImmediatelyOnTimeout]] **CloseHSClientCircuitsImmediatelyOnTimeout** **0**|**1**::
846 If 1, Tor will close unfinished hidden service client circuits
847 which have not moved closer to connecting to their destination
848 hidden service when their internal state has not changed for the
849 duration of the current circuit-build timeout. Otherwise, such
850 circuits will be left open, in the hope that they will finish
851 connecting to their destination hidden services. In either case,
852 another set of introduction and rendezvous circuits for the same
853 destination hidden service will be launched. (Default: 0)
855 [[CloseHSServiceRendCircuitsImmediatelyOnTimeout]] **CloseHSServiceRendCircuitsImmediatelyOnTimeout** **0**|**1**::
856 If 1, Tor will close unfinished hidden-service-side rendezvous
857 circuits after the current circuit-build timeout. Otherwise, such
858 circuits will be left open, in the hope that they will finish
859 connecting to their destinations. In either case, another
860 rendezvous circuit for the same destination client will be
861 launched. (Default: 0)
863 [[LongLivedPorts]] **LongLivedPorts** __PORTS__::
864 A list of ports for services that tend to have long-running connections
865 (e.g. chat and interactive shells). Circuits for streams that use these
866 ports will contain only high-uptime nodes, to reduce the chance that a node
867 will go down before the stream is finished. Note that the list is also
868 honored for circuits (both client and service side) involving hidden
869 services whose virtual port is in this list. (Default: 21, 22, 706,
870 1863, 5050, 5190, 5222, 5223, 6523, 6667, 6697, 8300)
872 [[MapAddress]] **MapAddress** __address__ __newaddress__::
873 When a request for address arrives to Tor, it will transform to newaddress
874 before processing it. For example, if you always want connections to
875 www.example.com to exit via __torserver__ (where __torserver__ is the
876 nickname of the server), use "MapAddress www.example.com
877 www.example.com.torserver.exit". If the value is prefixed with a
878 "\*.", matches an entire domain. For example, if you
879 always want connections to example.com and any if its subdomains
881 __torserver__ (where __torserver__ is the nickname of the server), use
882 "MapAddress \*.example.com \*.example.com.torserver.exit". (Note the
883 leading "*." in each part of the directive.) You can also redirect all
884 subdomains of a domain to a single address. For example, "MapAddress
885 *.example.com www.example.com". +
889 1. When evaluating MapAddress expressions Tor stops when it hits the most
890 recently added expression that matches the requested address. So if you
891 have the following in your torrc, www.torproject.org will map to 1.1.1.1:
893 MapAddress www.torproject.org 2.2.2.2
894 MapAddress www.torproject.org 1.1.1.1
896 2. Tor evaluates the MapAddress configuration until it finds no matches. So
897 if you have the following in your torrc, www.torproject.org will map to
900 MapAddress 1.1.1.1 2.2.2.2
901 MapAddress www.torproject.org 1.1.1.1
903 3. The following MapAddress expression is invalid (and will be
904 ignored) because you cannot map from a specific address to a wildcard
907 MapAddress www.torproject.org *.torproject.org.torserver.exit
909 4. Using a wildcard to match only part of a string (as in *ample.com) is
912 [[NewCircuitPeriod]] **NewCircuitPeriod** __NUM__::
913 Every NUM seconds consider whether to build a new circuit. (Default: 30
916 [[MaxCircuitDirtiness]] **MaxCircuitDirtiness** __NUM__::
917 Feel free to reuse a circuit that was first used at most NUM seconds ago,
918 but never attach a new stream to a circuit that is too old. For hidden
919 services, this applies to the __last__ time a circuit was used, not the
920 first. (Default: 10 minutes)
922 [[MaxClientCircuitsPending]] **MaxClientCircuitsPending** __NUM__::
923 Do not allow more than NUM circuits to be pending at a time for handling
924 client streams. A circuit is pending if we have begun constructing it,
925 but it has not yet been completely constructed. (Default: 32)
927 [[NodeFamily]] **NodeFamily** __node__,__node__,__...__::
928 The Tor servers, defined by their identity fingerprints or nicknames,
929 constitute a "family" of similar or co-administered servers, so never use
930 any two of them in the same circuit. Defining a NodeFamily is only needed
931 when a server doesn't list the family itself (with MyFamily). This option
932 can be used multiple times. In addition to nodes, you can also list
933 IP address and ranges and country codes in {curly braces}.
935 [[EnforceDistinctSubnets]] **EnforceDistinctSubnets** **0**|**1**::
936 If 1, Tor will not put two servers whose IP addresses are "too close" on
937 the same circuit. Currently, two addresses are "too close" if they lie in
938 the same /16 range. (Default: 1)
940 [[SOCKSPort]] **SOCKSPort** \['address':]__port__|**auto** [_flags_] [_isolation flags_]::
941 Open this port to listen for connections from SOCKS-speaking
942 applications. Set this to 0 if you don't want to allow application
943 connections via SOCKS. Set it to "auto" to have Tor pick a port for
944 you. This directive can be specified multiple times to bind
945 to multiple addresses/ports. (Default: 9050) +
947 The _isolation flags_ arguments give Tor rules for which streams
948 received on this SOCKSPort are allowed to share circuits with one
949 another. Recognized isolation flags are:
950 **IsolateClientAddr**;;
951 Don't share circuits with streams from a different
952 client address. (On by default and strongly recommended;
953 you can disable it with **NoIsolateClientAddr**.)
954 **IsolateSOCKSAuth**;;
955 Don't share circuits with streams for which different
956 SOCKS authentication was provided. (On by default;
957 you can disable it with **NoIsolateSOCKSAuth**.)
958 **IsolateClientProtocol**;;
959 Don't share circuits with streams using a different protocol.
960 (SOCKS 4, SOCKS 5, TransPort connections, NATDPort connections,
961 and DNSPort requests are all considered to be different protocols.)
962 **IsolateDestPort**;;
963 Don't share circuits with streams targetting a different
965 **IsolateDestAddr**;;
966 Don't share circuits with streams targetting a different
968 **SessionGroup=**__INT__;;
969 If no other isolation rules would prevent it, allow streams
970 on this port to share circuits with streams from every other
971 port with the same session group. (By default, streams received
972 on different SOCKSPorts, TransPorts, etc are always isolated from one
973 another. This option overrides that behavior.)
975 [[OtherSOCKSPortFlags]]::
976 Other recognized __flags__ for a SOCKSPort are:
978 Tell exits to not connect to IPv4 addresses in response to SOCKS
979 requests on this connection.
981 Tell exits to allow IPv6 addresses in response to SOCKS requests on
982 this connection, so long as SOCKS5 is in use. (SOCKS4 can't handle
985 Tells exits that, if a host has both an IPv4 and an IPv6 address,
986 we would prefer to connect to it via IPv6. (IPv4 is the default.) +
988 NOTE: Although this option allows you to specify an IP address
989 other than localhost, you should do so only with extreme caution.
990 The SOCKS protocol is unencrypted and (as we use it)
991 unauthenticated, so exposing it in this way could leak your
992 information to anybody watching your network, and allow anybody
993 to use your computer as an open proxy. +
996 Tells the client to remember IPv4 DNS answers we receive from exit
997 nodes via this connection. (On by default.)
999 Tells the client to remember IPv6 DNS answers we receive from exit
1000 nodes via this connection.
1002 Tells the client to remember all DNS answers we receive from exit
1003 nodes via this connection.
1005 Tells the client to use any cached IPv4 DNS answers we have when making
1006 requests via this connection. (NOTE: This option, along UseIPv6Cache
1007 and UseDNSCache, can harm your anonymity, and probably
1008 won't help performance as much as you might expect. Use with care!)
1010 Tells the client to use any cached IPv6 DNS answers we have when making
1011 requests via this connection.
1013 Tells the client to use any cached DNS answers we have when making
1014 requests via this connection.
1015 **PreferIPv6Automap**;;
1016 When serving a hostname lookup request on this port that
1017 should get automapped (according to AutomapHostsOnResove),
1018 if we could return either an IPv4 or an IPv6 answer, prefer
1019 an IPv6 answer. (On by default.)
1020 **PreferSOCKSNoAuth**;;
1021 Ordinarily, when an application offers both "username/password
1022 authentication" and "no authentication" to Tor via SOCKS5, Tor
1023 selects username/password authentication so that IsolateSOCKSAuth can
1024 work. This can confuse some applications, if they offer a
1025 username/password combination then get confused when asked for
1026 one. You can disable this behavior, so that Tor will select "No
1027 authentication" when IsolateSOCKSAuth is disabled, or when this
1030 [[SOCKSListenAddress]] **SOCKSListenAddress** __IP__[:__PORT__]::
1031 Bind to this address to listen for connections from Socks-speaking
1032 applications. (Default: 127.0.0.1) You can also specify a port (e.g.
1033 192.168.0.1:9100). This directive can be specified multiple times to bind
1034 to multiple addresses/ports. (DEPRECATED: As of 0.2.3.x-alpha, you can
1035 now use multiple SOCKSPort entries, and provide addresses for SOCKSPort
1036 entries, so SOCKSListenAddress no longer has a purpose. For backward
1037 compatibility, SOCKSListenAddress is only allowed when SOCKSPort is just
1040 [[SocksPolicy]] **SocksPolicy** __policy__,__policy__,__...__::
1041 Set an entrance policy for this server, to limit who can connect to the
1042 SocksPort and DNSPort ports. The policies have the same form as exit
1043 policies below, except that port specifiers are ignored. Any address
1044 not matched by some entry in the policy is accepted.
1046 [[SocksTimeout]] **SocksTimeout** __NUM__::
1047 Let a socks connection wait NUM seconds handshaking, and NUM seconds
1048 unattached waiting for an appropriate circuit, before we fail it. (Default:
1051 [[TokenBucketRefillInterval]] **TokenBucketRefillInterval** __NUM__ [**msec**|**second**]::
1052 Set the refill interval of Tor's token bucket to NUM milliseconds.
1053 NUM must be between 1 and 1000, inclusive. Note that the configured
1054 bandwidth limits are still expressed in bytes per second: this
1055 option only affects the frequency with which Tor checks to see whether
1056 previously exhausted connections may read again. (Default: 100 msec)
1058 [[TrackHostExits]] **TrackHostExits** __host__,__.domain__,__...__::
1059 For each value in the comma separated list, Tor will track recent
1060 connections to hosts that match this value and attempt to reuse the same
1061 exit node for each. If the value is prepended with a \'.\', it is treated as
1062 matching an entire domain. If one of the values is just a \'.', it means
1063 match everything. This option is useful if you frequently connect to sites
1064 that will expire all your authentication cookies (i.e. log you out) if
1065 your IP address changes. Note that this option does have the disadvantage
1066 of making it more clear that a given history is associated with a single
1067 user. However, most people who would wish to observe this will observe it
1068 through cookies or other protocol-specific means anyhow.
1070 [[TrackHostExitsExpire]] **TrackHostExitsExpire** __NUM__::
1071 Since exit servers go up and down, it is desirable to expire the
1072 association between host and exit server after NUM seconds. The default is
1073 1800 seconds (30 minutes).
1075 [[UpdateBridgesFromAuthority]] **UpdateBridgesFromAuthority** **0**|**1**::
1076 When set (along with UseBridges), Tor will try to fetch bridge descriptors
1077 from the configured bridge authorities when feasible. It will fall back to
1078 a direct request if the authority responds with a 404. (Default: 0)
1080 [[UseBridges]] **UseBridges** **0**|**1**::
1081 When set, Tor will fetch descriptors for each bridge listed in the "Bridge"
1082 config lines, and use these relays as both entry guards and directory
1083 guards. (Default: 0)
1085 [[UseEntryGuards]] **UseEntryGuards** **0**|**1**::
1086 If this option is set to 1, we pick a few long-term entry servers, and try
1087 to stick with them. This is desirable because constantly changing servers
1088 increases the odds that an adversary who owns some servers will observe a
1089 fraction of your paths. (Default: 1)
1091 [[UseEntryGuardsAsDirGuards]] **UseEntryGuardsAsDirGuards** **0**|**1**::
1092 If this option is set to 1, and UseEntryGuards is also set to 1,
1093 we try to use our entry guards as directory
1094 guards, and failing that, pick more nodes to act as our directory guards.
1095 This helps prevent an adversary from enumerating clients. It's only
1096 available for clients (non-relay, non-bridge) that aren't configured to
1097 download any non-default directory material. It doesn't currently
1098 do anything when we lack a live consensus. (Default: 1)
1100 [[NumEntryGuards]] **NumEntryGuards** __NUM__::
1101 If UseEntryGuards is set to 1, we will try to pick a total of NUM routers
1102 as long-term entries for our circuits. If NUM is 0, we try to learn
1103 the number from the NumEntryGuards consensus parameter, and default
1104 to 3 if the consensus parameter isn't set. (Default: 0)
1106 [[NumDirectoryGuards]] **NumDirectoryGuards** __NUM__::
1107 If UseEntryGuardsAsDirectoryGuards is enabled, we try to make sure we
1108 have at least NUM routers to use as directory guards. If this option
1109 is set to 0, use the value from the NumDirectoryGuards consensus
1110 parameter, falling back to the value from NumEntryGuards if the
1111 consensus parameter is 0 or isn't set. (Default: 0)
1113 [[GuardLifetime]] **GuardLifetime** __N__ **days**|**weeks**|**months**::
1114 If nonzero, and UseEntryGuards is set, minimum time to keep a guard before
1115 picking a new one. If zero, we use the GuardLifetime parameter from the
1116 consensus directory. No value here may be less than 1 month or greater
1117 than 5 years; out-of-range values are clamped. (Default: 0)
1119 [[SafeSocks]] **SafeSocks** **0**|**1**::
1120 When this option is enabled, Tor will reject application connections that
1121 use unsafe variants of the socks protocol -- ones that only provide an IP
1122 address, meaning the application is doing a DNS resolve first.
1123 Specifically, these are socks4 and socks5 when not doing remote DNS.
1126 [[TestSocks]] **TestSocks** **0**|**1**::
1127 When this option is enabled, Tor will make a notice-level log entry for
1128 each connection to the Socks port indicating whether the request used a
1129 safe socks protocol or an unsafe one (see above entry on SafeSocks). This
1130 helps to determine whether an application using Tor is possibly leaking
1131 DNS requests. (Default: 0)
1133 [[WarnUnsafeSocks]] **WarnUnsafeSocks** **0**|**1**::
1134 When this option is enabled, Tor will warn whenever a request is
1135 received that only contains an IP address instead of a hostname. Allowing
1136 applications to do DNS resolves themselves is usually a bad idea and
1137 can leak your location to attackers. (Default: 1)
1139 [[VirtualAddrNetworkIPv4]] **VirtualAddrNetworkIPv4** __Address__/__bits__ +
1141 [[VirtualAddrNetworkIPv6]] **VirtualAddrNetworkIPv6** [__Address__]/__bits__::
1142 When Tor needs to assign a virtual (unused) address because of a MAPADDRESS
1143 command from the controller or the AutomapHostsOnResolve feature, Tor
1144 picks an unassigned address from this range. (Defaults:
1145 127.192.0.0/10 and [FE80::]/10 respectively.) +
1147 When providing proxy server service to a network of computers using a tool
1148 like dns-proxy-tor, change the IPv4 network to "10.192.0.0/10" or
1149 "172.16.0.0/12" and change the IPv6 network to "[FC00]/7".
1150 The default **VirtualAddrNetwork** address ranges on a
1151 properly configured machine will route to the loopback or link-local
1153 local use, no change to the default VirtualAddrNetwork setting is needed.
1155 [[AllowNonRFC953Hostnames]] **AllowNonRFC953Hostnames** **0**|**1**::
1156 When this option is disabled, Tor blocks hostnames containing illegal
1157 characters (like @ and :) rather than sending them to an exit node to be
1158 resolved. This helps trap accidental attempts to resolve URLs and so on.
1161 [[AllowDotExit]] **AllowDotExit** **0**|**1**::
1162 If enabled, we convert "www.google.com.foo.exit" addresses on the
1163 SocksPort/TransPort/NATDPort into "www.google.com" addresses that exit from
1164 the node "foo". Disabled by default since attacking websites and exit
1165 relays can use it to manipulate your path selection. (Default: 0)
1167 [[FastFirstHopPK]] **FastFirstHopPK** **0**|**1**|**auto**::
1168 When this option is disabled, Tor uses the public key step for the first
1169 hop of creating circuits. Skipping it is generally safe since we have
1170 already used TLS to authenticate the relay and to establish forward-secure
1171 keys. Turning this option off makes circuit building a little
1172 slower. Setting this option to "auto" takes advice from the authorities
1173 in the latest consensus about whether to use this feature. +
1175 Note that Tor will always use the public key step for the first hop if it's
1176 operating as a relay, and it will never use the public key step if it
1177 doesn't yet know the onion key of the first hop. (Default: auto)
1179 [[TransPort]] **TransPort** \['address':]__port__|**auto** [_isolation flags_]::
1180 Open this port to listen for transparent proxy connections. Set this to
1181 0 if you don't want to allow transparent proxy connections. Set the port
1182 to "auto" to have Tor pick a port for you. This directive can be
1183 specified multiple times to bind to multiple addresses/ports. See
1184 SOCKSPort for an explanation of isolation flags. +
1186 TransPort requires OS support for transparent proxies, such as BSDs' pf or
1187 Linux's IPTables. If you're planning to use Tor as a transparent proxy for
1188 a network, you'll want to examine and change VirtualAddrNetwork from the
1189 default setting. You'll also want to set the TransListenAddress option for
1190 the network you'd like to proxy. (Default: 0)
1192 [[TransListenAddress]] **TransListenAddress** __IP__[:__PORT__]::
1193 Bind to this address to listen for transparent proxy connections. (Default:
1194 127.0.0.1). This is useful for exporting a transparent proxy server to an
1195 entire network. (DEPRECATED: As of 0.2.3.x-alpha, you can
1196 now use multiple TransPort entries, and provide addresses for TransPort
1197 entries, so TransListenAddress no longer has a purpose. For backward
1198 compatibility, TransListenAddress is only allowed when TransPort is just
1201 [[TransProxyType]] **TransProxyType** **default**|**TPROXY**|**ipfw**|**pf-divert**::
1202 TransProxyType may only be enabled when there is transparent proxy listener
1205 Set this to "TPROXY" if you wish to be able to use the TPROXY Linux module
1206 to transparently proxy connections that are configured using the TransPort
1207 option. This setting lets the listener on the TransPort accept connections
1208 for all addresses, even when the TransListenAddress is configured for an
1209 internal address. Detailed information on how to configure the TPROXY
1210 feature can be found in the Linux kernel source tree in the file
1211 Documentation/networking/tproxy.txt.
1213 Set this option to "ipfw" to use the FreeBSD ipfw interface.
1215 On *BSD operating systems when using pf, set this to "pf-divert" to take
1216 advantage of +divert-to+ rules, which do not modify the packets like
1217 +rdr-to+ rules do. Detailed information on how to configure pf to use
1218 +divert-to+ rules can be found in the pf.conf(5) manual page. On OpenBSD,
1219 +divert-to+ is available to use on versions greater than or equal to
1222 Set this to "default", or leave it unconfigured, to use regular IPTables
1223 on Linux, or to use pf +rdr-to+ rules on *BSD systems.
1225 (Default: "default".)
1227 [[NATDPort]] **NATDPort** \['address':]__port__|**auto** [_isolation flags_]::
1228 Open this port to listen for connections from old versions of ipfw (as
1229 included in old versions of FreeBSD, etc) using the NATD protocol.
1230 Use 0 if you don't want to allow NATD connections. Set the port
1231 to "auto" to have Tor pick a port for you. This directive can be
1232 specified multiple times to bind to multiple addresses/ports. See
1233 SOCKSPort for an explanation of isolation flags. +
1235 This option is only for people who cannot use TransPort. (Default: 0)
1237 [[NATDListenAddress]] **NATDListenAddress** __IP__[:__PORT__]::
1238 Bind to this address to listen for NATD connections. (DEPRECATED: As of
1239 0.2.3.x-alpha, you can now use multiple NATDPort entries, and provide
1240 addresses for NATDPort entries, so NATDListenAddress no longer has a
1241 purpose. For backward compatibility, NATDListenAddress is only allowed
1242 when NATDPort is just a port number.)
1244 [[AutomapHostsOnResolve]] **AutomapHostsOnResolve** **0**|**1**::
1245 When this option is enabled, and we get a request to resolve an address
1246 that ends with one of the suffixes in **AutomapHostsSuffixes**, we map an
1247 unused virtual address to that address, and return the new virtual address.
1248 This is handy for making ".onion" addresses work with applications that
1249 resolve an address and then connect to it. (Default: 0)
1251 [[AutomapHostsSuffixes]] **AutomapHostsSuffixes** __SUFFIX__,__SUFFIX__,__...__::
1252 A comma-separated list of suffixes to use with **AutomapHostsOnResolve**.
1253 The "." suffix is equivalent to "all addresses." (Default: .exit,.onion).
1255 [[DNSPort]] **DNSPort** \['address':]__port__|**auto** [_isolation flags_]::
1256 If non-zero, open this port to listen for UDP DNS requests, and resolve
1257 them anonymously. This port only handles A, AAAA, and PTR requests---it
1258 doesn't handle arbitrary DNS request types. Set the port to "auto" to
1259 have Tor pick a port for
1260 you. This directive can be specified multiple times to bind to multiple
1261 addresses/ports. See SOCKSPort for an explanation of isolation
1264 [[DNSListenAddress]] **DNSListenAddress** __IP__[:__PORT__]::
1265 Bind to this address to listen for DNS connections. (DEPRECATED: As of
1266 0.2.3.x-alpha, you can now use multiple DNSPort entries, and provide
1267 addresses for DNSPort entries, so DNSListenAddress no longer has a
1268 purpose. For backward compatibility, DNSListenAddress is only allowed
1269 when DNSPort is just a port number.)
1271 [[ClientDNSRejectInternalAddresses]] **ClientDNSRejectInternalAddresses** **0**|**1**::
1272 If true, Tor does not believe any anonymously retrieved DNS answer that
1273 tells it that an address resolves to an internal address (like 127.0.0.1 or
1274 192.168.0.1). This option prevents certain browser-based attacks; don't
1275 turn it off unless you know what you're doing. (Default: 1)
1277 [[ClientRejectInternalAddresses]] **ClientRejectInternalAddresses** **0**|**1**::
1278 If true, Tor does not try to fulfill requests to connect to an internal
1279 address (like 127.0.0.1 or 192.168.0.1) __unless a exit node is
1280 specifically requested__ (for example, via a .exit hostname, or a
1281 controller request). (Default: 1)
1283 [[DownloadExtraInfo]] **DownloadExtraInfo** **0**|**1**::
1284 If true, Tor downloads and caches "extra-info" documents. These documents
1285 contain information about servers other than the information in their
1286 regular router descriptors. Tor does not use this information for anything
1287 itself; to save bandwidth, leave this option turned off. (Default: 0)
1289 [[WarnPlaintextPorts]] **WarnPlaintextPorts** __port__,__port__,__...__::
1290 Tells Tor to issue a warnings whenever the user tries to make an anonymous
1291 connection to one of these ports. This option is designed to alert users
1292 to services that risk sending passwords in the clear. (Default:
1295 [[RejectPlaintextPorts]] **RejectPlaintextPorts** __port__,__port__,__...__::
1296 Like WarnPlaintextPorts, but instead of warning about risky port uses, Tor
1297 will instead refuse to make the connection. (Default: None)
1299 [[AllowSingleHopCircuits]] **AllowSingleHopCircuits** **0**|**1**::
1300 When this option is set, the attached Tor controller can use relays
1301 that have the **AllowSingleHopExits** option turned on to build
1302 one-hop Tor connections. (Default: 0)
1304 [[OptimisticData]] **OptimisticData** **0**|**1**|**auto**::
1305 When this option is set, and Tor is using an exit node that supports
1306 the feature, it will try optimistically to send data to the exit node
1307 without waiting for the exit node to report whether the connection
1308 succeeded. This can save a round-trip time for protocols like HTTP
1309 where the client talks first. If OptimisticData is set to **auto**,
1310 Tor will look at the UseOptimisticData parameter in the networkstatus.
1313 [[Tor2webMode]] **Tor2webMode** **0**|**1**::
1314 When this option is set, Tor connects to hidden services
1315 **non-anonymously**. This option also disables client connections to
1316 non-hidden-service hostnames through Tor. It **must only** be used when
1317 running a tor2web Hidden Service web proxy.
1318 To enable this option the compile time flag --enable-tor2webmode must be
1319 specified. (Default: 0)
1321 [[UseMicrodescriptors]] **UseMicrodescriptors** **0**|**1**|**auto**::
1322 Microdescriptors are a smaller version of the information that Tor needs
1323 in order to build its circuits. Using microdescriptors makes Tor clients
1324 download less directory information, thus saving bandwidth. Directory
1325 caches need to fetch regular descriptors and microdescriptors, so this
1326 option doesn't save any bandwidth for them. If this option is set to
1327 "auto" (recommended) then it is on for all clients that do not set
1328 FetchUselessDescriptors. (Default: auto)
1330 [[UseNTorHandshake]] **UseNTorHandshake** **0**|**1**|**auto**::
1331 The "ntor" circuit-creation handshake is faster and (we think) more
1332 secure than the original ("TAP") circuit handshake, but starting to use
1333 it too early might make your client stand out. If this option is 0, your
1334 Tor client won't use the ntor handshake. If it's 1, your Tor client
1335 will use the ntor handshake to extend circuits through servers that
1336 support it. If this option is "auto", then your client
1337 will use the ntor handshake once enough directory authorities recommend
1340 [[PathBiasCircThreshold]] **PathBiasCircThreshold** __NUM__ +
1342 [[PathBiasNoticeRate]] **PathBiasNoticeRate** __NUM__ +
1344 [[PathBiasWarnRate]] **PathBiasWarnRate** __NUM__ +
1346 [[PathBiasExtremeRate]] **PathBiasExtremeRate** __NUM__ +
1348 [[PathBiasDropGuards]] **PathBiasDropGuards** __NUM__ +
1350 [[PathBiasScaleThreshold]] **PathBiasScaleThreshold** __NUM__::
1351 These options override the default behavior of Tor's (**currently
1352 experimental**) path bias detection algorithm. To try to find broken or
1353 misbehaving guard nodes, Tor looks for nodes where more than a certain
1354 fraction of circuits through that guard fail to get built.
1356 The PathBiasCircThreshold option controls how many circuits we need to build
1357 through a guard before we make these checks. The PathBiasNoticeRate,
1358 PathBiasWarnRate and PathBiasExtremeRate options control what fraction of
1359 circuits must succeed through a guard so we won't write log messages.
1360 If less than PathBiasExtremeRate circuits succeed *and* PathBiasDropGuards
1361 is set to 1, we disable use of that guard. +
1363 When we have seen more than PathBiasScaleThreshold
1364 circuits through a guard, we scale our observations by 0.5 (governed by
1365 the consensus) so that new observations don't get swamped by old ones. +
1367 By default, or if a negative value is provided for one of these options,
1368 Tor uses reasonable defaults from the networkstatus consensus document.
1369 If no defaults are available there, these options default to 150, .70,
1370 .50, .30, 0, and 300 respectively.
1372 [[PathBiasUseThreshold]] **PathBiasUseThreshold** __NUM__ +
1374 [[PathBiasNoticeUseRate]] **PathBiasNoticeUseRate** __NUM__ +
1376 [[PathBiasExtremeUseRate]] **PathBiasExtremeUseRate** __NUM__ +
1378 [[PathBiasScaleUseThreshold]] **PathBiasScaleUseThreshold** __NUM__::
1379 Similar to the above options, these options override the default behavior
1380 of Tor's (**currently experimental**) path use bias detection algorithm.
1382 Where as the path bias parameters govern thresholds for successfully
1383 building circuits, these four path use bias parameters govern thresholds
1384 only for circuit usage. Circuits which receive no stream usage
1385 are not counted by this detection algorithm. A used circuit is considered
1386 successful if it is capable of carrying streams or otherwise receiving
1387 well-formed responses to RELAY cells.
1389 By default, or if a negative value is provided for one of these options,
1390 Tor uses reasonable defaults from the networkstatus consensus document.
1391 If no defaults are available there, these options default to 20, .80,
1392 .60, and 100, respectively.
1394 [[ClientUseIPv6]] **ClientUseIPv6** **0**|**1**::
1395 If this option is set to 1, Tor might connect to entry nodes over
1396 IPv6. Note that clients configured with an IPv6 address in a
1397 **Bridge** line will try connecting over IPv6 even if
1398 **ClientUseIPv6** is set to 0. (Default: 0)
1400 [[ClientPreferIPv6ORPort]] **ClientPreferIPv6ORPort** **0**|**1**::
1401 If this option is set to 1, Tor prefers an OR port with an IPv6
1402 address over one with IPv4 if a given entry node has both. Other
1403 things may influence the choice. This option breaks a tie to the
1404 favor of IPv6. (Default: 0)
1406 [[PathsNeededToBuildCircuits]] **PathsNeededToBuildCircuits** __NUM__::
1407 Tor clients don't build circuits for user traffic until they know
1408 about enough of the network so that they could potentially construct
1409 enough of the possible paths through the network. If this option
1410 is set to a fraction between 0.25 and 0.95, Tor won't build circuits
1411 until it has enough descriptors or microdescriptors to construct
1412 that fraction of possible paths. Note that setting this option too low
1413 can make your Tor client less anonymous, and setting it too high can
1414 prevent your Tor client from bootstrapping. If this option is negative,
1415 Tor will use a default value chosen by the directory
1416 authorities. (Default: -1.)
1418 [[Support022HiddenServices]] **Support022HiddenServices** **0**|**1**|**auto**::
1419 Tor hidden services running versions before 0.2.3.x required clients to
1420 send timestamps, which can potentially be used to distinguish clients
1421 whose view of the current time is skewed. If this option is set to 0, we
1422 do not send this timestamp, and hidden services on obsolete Tor versions
1423 will not work. If this option is set to 1, we send the timestamp. If
1424 this optoin is "auto", we take a recommendation from the latest consensus
1425 document. (Default: auto)
1431 The following options are useful only for servers (that is, if ORPort
1434 [[Address]] **Address** __address__::
1435 The IP address or fully qualified domain name of this server (e.g.
1436 moria.mit.edu). You can leave this unset, and Tor will guess your IP
1437 address. This IP address is the one used to tell clients and other
1438 servers where to find your Tor server; it doesn't affect the IP that your
1439 Tor client binds to. To bind to a different address, use the
1440 *ListenAddress and OutboundBindAddress options.
1442 [[AllowSingleHopExits]] **AllowSingleHopExits** **0**|**1**::
1443 This option controls whether clients can use this server as a single hop
1444 proxy. If set to 1, clients can use this server as an exit even if it is
1445 the only hop in the circuit. Note that most clients will refuse to use
1446 servers that set this option, since most clients have
1447 ExcludeSingleHopRelays set. (Default: 0)
1449 [[AssumeReachable]] **AssumeReachable** **0**|**1**::
1450 This option is used when bootstrapping a new Tor network. If set to 1,
1451 don't do self-reachability testing; just upload your server descriptor
1452 immediately. If **AuthoritativeDirectory** is also set, this option
1453 instructs the dirserver to bypass remote reachability testing too and list
1454 all connected servers as running.
1456 [[BridgeRelay]] **BridgeRelay** **0**|**1**::
1457 Sets the relay to act as a "bridge" with respect to relaying connections
1458 from bridge users to the Tor network. It mainly causes Tor to publish a
1459 server descriptor to the bridge database, rather than publishing a relay
1460 descriptor to the public directory authorities.
1462 [[ContactInfo]] **ContactInfo** __email_address__::
1463 Administrative contact information for this relay or bridge. This line
1464 can be used to contact you if your relay or bridge is misconfigured or
1465 something else goes wrong. Note that we archive and publish all
1466 descriptors containing these lines and that Google indexes them, so
1467 spammers might also collect them. You may want to obscure the fact
1468 that it's an email address and/or generate a new address for this
1471 [[ExitPolicy]] **ExitPolicy** __policy__,__policy__,__...__::
1472 Set an exit policy for this server. Each policy is of the form
1473 "**accept**|**reject** __ADDR__[/__MASK__][:__PORT__]". If /__MASK__ is
1474 omitted then this policy just applies to the host given. Instead of giving
1475 a host or network you can also use "\*" to denote the universe (0.0.0.0/0).
1476 __PORT__ can be a single port number, an interval of ports
1477 "__FROM_PORT__-__TO_PORT__", or "\*". If __PORT__ is omitted, that means
1480 For example, "accept 18.7.22.69:\*,reject 18.0.0.0/8:\*,accept \*:\*" would
1481 reject any traffic destined for MIT except for web.mit.edu, and accept
1484 To specify all internal and link-local networks (including 0.0.0.0/8,
1485 169.254.0.0/16, 127.0.0.0/8, 192.168.0.0/16, 10.0.0.0/8, and
1486 172.16.0.0/12), you can use the "private" alias instead of an address.
1487 These addresses are rejected by default (at the beginning of your exit
1488 policy), along with your public IP address, unless you set the
1489 ExitPolicyRejectPrivate config option to 0. For example, once you've done
1490 that, you could allow HTTP to 127.0.0.1 and block all other connections to
1491 internal networks with "accept 127.0.0.1:80,reject private:\*", though that
1492 may also allow connections to your own computer that are addressed to its
1493 public (external) IP address. See RFC 1918 and RFC 3330 for more details
1494 about internal and reserved IP address space. +
1496 Tor also allow IPv6 exit policy entries. For instance, "reject6 [FC00::]/7:*"
1497 rejects all destinations that share 7 most significant bit prefix with
1498 address FC00::. Respectively, "accept6 [C000::]/3:*" accepts all destinations
1499 that share 3 most significant bit prefix with address C000::. +
1501 This directive can be specified multiple times so you don't have to put it
1504 Policies are considered first to last, and the first match wins. If you
1505 want to \_replace_ the default exit policy, end your exit policy with
1506 either a reject \*:* or an accept \*:*. Otherwise, you're \_augmenting_
1507 (prepending to) the default exit policy. The default exit policy is: +
1521 [[ExitPolicyRejectPrivate]] **ExitPolicyRejectPrivate** **0**|**1**::
1522 Reject all private (local) networks, along with your own public IP address,
1523 at the beginning of your exit policy. See above entry on ExitPolicy.
1526 [[IPv6Exit]] **IPv6Exit** **0**|**1**::
1527 If set, and we are an exit node, allow clients to use us for IPv6
1528 traffic. (Default: 0)
1530 [[MaxOnionQueueDelay]] **MaxOnionQueueDelay** __NUM__ [**msec**|**second**]::
1531 If we have more onionskins queued for processing than we can process in
1532 this amount of time, reject new ones. (Default: 1750 msec)
1534 [[MyFamily]] **MyFamily** __node__,__node__,__...__::
1535 Declare that this Tor server is controlled or administered by a group or
1536 organization identical or similar to that of the other servers, defined by
1537 their identity fingerprints or nicknames. When two servers both declare
1538 that they are in the same \'family', Tor clients will not use them in the
1539 same circuit. (Each server only needs to list the other servers in its
1540 family; it doesn't need to list itself, but it won't hurt.) Do not list
1541 any bridge relay as it would compromise its concealment.
1543 When listing a node, it's better to list it by fingerprint than by
1544 nickname: fingerprints are more reliable.
1546 [[Nickname]] **Nickname** __name__::
1547 Set the server's nickname to \'name'. Nicknames must be between 1 and 19
1548 characters inclusive, and must contain only the characters [a-zA-Z0-9].
1550 [[NumCPUs]] **NumCPUs** __num__::
1551 How many processes to use at once for decrypting onionskins and other
1552 parallelizable operations. If this is set to 0, Tor will try to detect
1553 how many CPUs you have, defaulting to 1 if it can't tell. (Default: 0)
1555 [[ORPort]] **ORPort** \['address':]__PORT__|**auto** [_flags_]::
1556 Advertise this port to listen for connections from Tor clients and
1557 servers. This option is required to be a Tor server.
1558 Set it to "auto" to have Tor pick a port for you. Set it to 0 to not
1559 run an ORPort at all. This option can occur more than once. (Default: 0)
1561 Tor recognizes these flags on each ORPort:
1563 By default, we bind to a port and tell our users about it. If
1564 NoAdvertise is specified, we don't advertise, but listen anyway. This
1565 can be useful if the port everybody will be connecting to (for
1566 example, one that's opened on our firewall) is somewhere else.
1568 By default, we bind to a port and tell our users about it. If
1569 NoListen is specified, we don't bind, but advertise anyway. This
1570 can be useful if something else (for example, a firewall's port
1571 forwarding configuration) is causing connections to reach us.
1573 If the address is absent, or resolves to both an IPv4 and an IPv6
1574 address, only listen to the IPv4 address.
1576 If the address is absent, or resolves to both an IPv4 and an IPv6
1577 address, only listen to the IPv6 address.
1579 For obvious reasons, NoAdvertise and NoListen are mutually exclusive, and
1580 IPv4Only and IPv6Only are mutually exclusive.
1582 [[ORListenAddress]] **ORListenAddress** __IP__[:__PORT__]::
1583 Bind to this IP address to listen for connections from Tor clients and
1584 servers. If you specify a port, bind to this port rather than the one
1585 specified in ORPort. (Default: 0.0.0.0) This directive can be specified
1586 multiple times to bind to multiple addresses/ports.
1588 This option is deprecated; you can get the same behavior with ORPort now
1589 that it supports NoAdvertise and explicit addresses.
1591 [[PortForwarding]] **PortForwarding** **0**|**1**::
1592 Attempt to automatically forward the DirPort and ORPort on a NAT router
1593 connecting this Tor server to the Internet. If set, Tor will try both
1594 NAT-PMP (common on Apple routers) and UPnP (common on routers from other
1595 manufacturers). (Default: 0)
1597 [[PortForwardingHelper]] **PortForwardingHelper** __filename__|__pathname__::
1598 If PortForwarding is set, use this executable to configure the forwarding.
1599 If set to a filename, the system path will be searched for the executable.
1600 If set to a path, only the specified path will be executed.
1601 (Default: tor-fw-helper)
1603 [[PublishServerDescriptor]] **PublishServerDescriptor** **0**|**1**|**v3**|**bridge**,**...**::
1604 This option specifies which descriptors Tor will publish when acting as
1606 choose multiple arguments, separated by commas.
1608 If this option is set to 0, Tor will not publish its
1609 descriptors to any directories. (This is useful if you're testing
1610 out your server, or if you're using a Tor controller that handles directory
1611 publishing for you.) Otherwise, Tor will publish its descriptors of all
1612 type(s) specified. The default is "1",
1613 which means "if running as a server, publish the
1614 appropriate descriptors to the authorities".
1616 [[ShutdownWaitLength]] **ShutdownWaitLength** __NUM__::
1617 When we get a SIGINT and we're a server, we begin shutting down:
1618 we close listeners and start refusing new circuits. After **NUM**
1619 seconds, we exit. If we get a second SIGINT, we exit immediately.
1620 (Default: 30 seconds)
1622 [[SSLKeyLifetime]] **SSLKeyLifetime** __N__ **minutes**|**hours**|**days**|**weeks**::
1623 When creating a link certificate for our outermost SSL handshake,
1624 set its lifetime to this amount of time. If set to 0, Tor will choose
1625 some reasonable random defaults. (Default: 0)
1627 [[HeartbeatPeriod]] **HeartbeatPeriod** __N__ **minutes**|**hours**|**days**|**weeks**::
1628 Log a heartbeat message every **HeartbeatPeriod** seconds. This is
1629 a log level __notice__ message, designed to let you know your Tor
1630 server is still alive and doing useful things. Settings this
1631 to 0 will disable the heartbeat. (Default: 6 hours)
1633 [[AccountingMax]] **AccountingMax** __N__ **bytes**|**KBytes**|**MBytes**|**GBytes**|**KBits**|**MBits**|**GBits**|**TBytes**::
1634 Never send more than the specified number of bytes in a given accounting
1635 period, or receive more than that number in the period. For example, with
1636 AccountingMax set to 1 GByte, a server could send 900 MBytes and
1637 receive 800 MBytes and continue running. It will only hibernate once
1638 one of the two reaches 1 GByte. When the number of bytes gets low,
1639 Tor will stop accepting new connections and circuits. When the
1640 number of bytes is exhausted, Tor will hibernate until some
1641 time in the next accounting period. To prevent all servers from waking at
1642 the same time, Tor will also wait until a random point in each period
1643 before waking up. If you have bandwidth cost issues, enabling hibernation
1644 is preferable to setting a low bandwidth, since it provides users with a
1645 collection of fast servers that are up some of the time, which is more
1646 useful than a set of slow servers that are always "available".
1648 [[AccountingStart]] **AccountingStart** **day**|**week**|**month** [__day__] __HH:MM__::
1649 Specify how long accounting periods last. If **month** is given, each
1650 accounting period runs from the time __HH:MM__ on the __dayth__ day of one
1651 month to the same day and time of the next. (The day must be between 1 and
1652 28.) If **week** is given, each accounting period runs from the time __HH:MM__
1653 of the __dayth__ day of one week to the same day and time of the next week,
1654 with Monday as day 1 and Sunday as day 7. If **day** is given, each
1655 accounting period runs from the time __HH:MM__ each day to the same time on
1656 the next day. All times are local, and given in 24-hour time. (Default:
1659 [[RefuseUnknownExits]] **RefuseUnknownExits** **0**|**1**|**auto**::
1660 Prevent nodes that don't appear in the consensus from exiting using this
1661 relay. If the option is 1, we always block exit attempts from such
1662 nodes; if it's 0, we never do, and if the option is "auto", then we do
1663 whatever the authorities suggest in the consensus (and block if the consensus
1664 is quiet on the issue). (Default: auto)
1666 [[ServerDNSResolvConfFile]] **ServerDNSResolvConfFile** __filename__::
1667 Overrides the default DNS configuration with the configuration in
1668 __filename__. The file format is the same as the standard Unix
1669 "**resolv.conf**" file (7). This option, like all other ServerDNS options,
1670 only affects name lookups that your server does on behalf of clients.
1671 (Defaults to use the system DNS configuration.)
1673 [[ServerDNSAllowBrokenConfig]] **ServerDNSAllowBrokenConfig** **0**|**1**::
1674 If this option is false, Tor exits immediately if there are problems
1675 parsing the system DNS configuration or connecting to nameservers.
1676 Otherwise, Tor continues to periodically retry the system nameservers until
1677 it eventually succeeds. (Default: 1)
1679 [[ServerDNSSearchDomains]] **ServerDNSSearchDomains** **0**|**1**::
1680 If set to 1, then we will search for addresses in the local search domain.
1681 For example, if this system is configured to believe it is in
1682 "example.com", and a client tries to connect to "www", the client will be
1683 connected to "www.example.com". This option only affects name lookups that
1684 your server does on behalf of clients. (Default: 0)
1686 [[ServerDNSDetectHijacking]] **ServerDNSDetectHijacking** **0**|**1**::
1687 When this option is set to 1, we will test periodically to determine
1688 whether our local nameservers have been configured to hijack failing DNS
1689 requests (usually to an advertising site). If they are, we will attempt to
1690 correct this. This option only affects name lookups that your server does
1691 on behalf of clients. (Default: 1)
1693 [[ServerDNSTestAddresses]] **ServerDNSTestAddresses** __address__,__address__,__...__::
1694 When we're detecting DNS hijacking, make sure that these __valid__ addresses
1695 aren't getting redirected. If they are, then our DNS is completely useless,
1696 and we'll reset our exit policy to "reject *:*". This option only affects
1697 name lookups that your server does on behalf of clients. (Default:
1698 "www.google.com, www.mit.edu, www.yahoo.com, www.slashdot.org")
1700 [[ServerDNSAllowNonRFC953Hostnames]] **ServerDNSAllowNonRFC953Hostnames** **0**|**1**::
1701 When this option is disabled, Tor does not try to resolve hostnames
1702 containing illegal characters (like @ and :) rather than sending them to an
1703 exit node to be resolved. This helps trap accidental attempts to resolve
1704 URLs and so on. This option only affects name lookups that your server does
1705 on behalf of clients. (Default: 0)
1707 [[BridgeRecordUsageByCountry]] **BridgeRecordUsageByCountry** **0**|**1**::
1708 When this option is enabled and BridgeRelay is also enabled, and we have
1709 GeoIP data, Tor keeps a per-country count of how many client
1710 addresses have contacted it so that it can help the bridge authority guess
1711 which countries have blocked access to it. (Default: 1)
1713 [[ServerDNSRandomizeCase]] **ServerDNSRandomizeCase** **0**|**1**::
1714 When this option is set, Tor sets the case of each character randomly in
1715 outgoing DNS requests, and makes sure that the case matches in DNS replies.
1716 This so-called "0x20 hack" helps resist some types of DNS poisoning attack.
1717 For more information, see "Increased DNS Forgery Resistance through
1718 0x20-Bit Encoding". This option only affects name lookups that your server
1719 does on behalf of clients. (Default: 1)
1721 [[GeoIPFile]] **GeoIPFile** __filename__::
1722 A filename containing IPv4 GeoIP data, for use with by-country statistics.
1724 [[GeoIPv6File]] **GeoIPv6File** __filename__::
1725 A filename containing IPv6 GeoIP data, for use with by-country statistics.
1727 [[TLSECGroup]] **TLSECGroup** **P224**|**P256**::
1728 What EC group should we try to use for incoming TLS connections?
1729 P224 is faster, but makes us stand out more. Has no effect if
1730 we're a client, or if our OpenSSL version lacks support for ECDHE.
1733 [[CellStatistics]] **CellStatistics** **0**|**1**::
1734 When this option is enabled, Tor writes statistics on the mean time that
1735 cells spend in circuit queues to disk every 24 hours. (Default: 0)
1737 [[DirReqStatistics]] **DirReqStatistics** **0**|**1**::
1738 When this option is enabled, a Tor directory writes statistics on the
1739 number and response time of network status requests to disk every 24
1742 [[EntryStatistics]] **EntryStatistics** **0**|**1**::
1743 When this option is enabled, Tor writes statistics on the number of
1744 directly connecting clients to disk every 24 hours. (Default: 0)
1746 [[ExitPortStatistics]] **ExitPortStatistics** **0**|**1**::
1747 When this option is enabled, Tor writes statistics on the number of relayed
1748 bytes and opened stream per exit port to disk every 24 hours. (Default: 0)
1750 [[ConnDirectionStatistics]] **ConnDirectionStatistics** **0**|**1**::
1751 When this option is enabled, Tor writes statistics on the bidirectional use
1752 of connections to disk every 24 hours. (Default: 0)
1754 [[ExtraInfoStatistics]] **ExtraInfoStatistics** **0**|**1**::
1755 When this option is enabled, Tor includes previously gathered statistics in
1756 its extra-info documents that it uploads to the directory authorities.
1759 [[ExtendAllowPrivateAddresses]] **ExtendAllowPrivateAddresses** **0**|**1**::
1760 When this option is enabled, Tor routers allow EXTEND request to
1761 localhost, RFC1918 addresses, and so on. This can create security issues;
1762 you should probably leave it off. (Default: 0)
1764 [[MaxMemInQueues]] **MaxMemInQueues** __N__ **bytes**|**KB**|**MB**|**GB**::
1765 This option configures a threshold above which Tor will assume that it
1766 needs to stop queueing or buffering data because it's about to run out of
1767 memory. If it hits this threshold, it will begin killing circuits until
1768 it has recovered at least 10% of this memory. Do not set this option too
1769 low, or your relay may be unreliable under load. This option only
1770 affects some queues, so the actual process size will be larger than
1771 this. If this option is set to 0, Tor will try to pick a reasonable
1772 default based on your system's physical memory. (Default: 0)
1774 DIRECTORY SERVER OPTIONS
1775 ------------------------
1777 The following options are useful only for directory servers (that is,
1778 if DirPort is non-zero):
1780 [[DirPortFrontPage]] **DirPortFrontPage** __FILENAME__::
1781 When this option is set, it takes an HTML file and publishes it as "/" on
1782 the DirPort. Now relay operators can provide a disclaimer without needing
1783 to set up a separate webserver. There's a sample disclaimer in
1784 contrib/operator-tools/tor-exit-notice.html.
1786 [[HidServDirectoryV2]] **HidServDirectoryV2** **0**|**1**::
1787 When this option is set, Tor accepts and serves v2 hidden service
1788 descriptors. Setting DirPort is not required for this, because clients
1789 connect via the ORPort by default. (Default: 1)
1791 [[DirPort]] **DirPort** \['address':]__PORT__|**auto** [_flags_]::
1792 If this option is nonzero, advertise the directory service on this port.
1793 Set it to "auto" to have Tor pick a port for you. This option can occur
1794 more than once, but only one advertised DirPort is supported: all
1795 but one DirPort must have the **NoAdvertise** flag set. (Default: 0)
1797 The same flags are supported here as are supported by ORPort.
1799 [[DirListenAddress]] **DirListenAddress** __IP__[:__PORT__]::
1800 Bind the directory service to this address. If you specify a port, bind to
1801 this port rather than the one specified in DirPort. (Default: 0.0.0.0)
1802 This directive can be specified multiple times to bind to multiple
1805 This option is deprecated; you can get the same behavior with DirPort now
1806 that it supports NoAdvertise and explicit addresses.
1808 [[DirPolicy]] **DirPolicy** __policy__,__policy__,__...__::
1809 Set an entrance policy for this server, to limit who can connect to the
1810 directory ports. The policies have the same form as exit policies above,
1811 except that port specifiers are ignored. Any address not matched by
1812 some entry in the policy is accepted.
1815 DIRECTORY AUTHORITY SERVER OPTIONS
1816 ----------------------------------
1818 The following options enable operation as a directory authority, and
1819 control how Tor behaves as a directory authority. You should not need
1820 to adjust any of them if you're running a regular relay or exit server
1821 on the public Tor network.
1823 [[AuthoritativeDirectory]] **AuthoritativeDirectory** **0**|**1**::
1824 When this option is set to 1, Tor operates as an authoritative directory
1825 server. Instead of caching the directory, it generates its own list of
1826 good servers, signs it, and sends that to the clients. Unless the clients
1827 already have you listed as a trusted directory, you probably do not want
1828 to set this option. Please coordinate with the other admins at
1829 tor-ops@torproject.org if you think you should be a directory.
1831 [[V3AuthoritativeDirectory]] **V3AuthoritativeDirectory** **0**|**1**::
1832 When this option is set in addition to **AuthoritativeDirectory**, Tor
1833 generates version 3 network statuses and serves descriptors, etc as
1834 described in doc/spec/dir-spec.txt (for Tor clients and servers running at
1837 [[VersioningAuthoritativeDirectory]] **VersioningAuthoritativeDirectory** **0**|**1**::
1838 When this option is set to 1, Tor adds information on which versions of
1839 Tor are still believed safe for use to the published directory. Each
1840 version 1 authority is automatically a versioning authority; version 2
1841 authorities provide this service optionally. See **RecommendedVersions**,
1842 **RecommendedClientVersions**, and **RecommendedServerVersions**.
1844 [[NamingAuthoritativeDirectory]] **NamingAuthoritativeDirectory** **0**|**1**::
1845 When this option is set to 1, then the server advertises that it has
1846 opinions about nickname-to-fingerprint bindings. It will include these
1847 opinions in its published network-status pages, by listing servers with
1848 the flag "Named" if a correct binding between that nickname and fingerprint
1849 has been registered with the dirserver. Naming dirservers will refuse to
1850 accept or publish descriptors that contradict a registered binding. See
1851 **approved-routers** in the **FILES** section below.
1853 [[RecommendedVersions]] **RecommendedVersions** __STRING__::
1854 STRING is a comma-separated list of Tor versions currently believed to be
1855 safe. The list is included in each directory, and nodes which pull down the
1856 directory learn whether they need to upgrade. This option can appear
1857 multiple times: the values from multiple lines are spliced together. When
1858 this is set then **VersioningAuthoritativeDirectory** should be set too.
1860 [[RecommendedClientVersions]] **RecommendedClientVersions** __STRING__::
1861 STRING is a comma-separated list of Tor versions currently believed to be
1862 safe for clients to use. This information is included in version 2
1863 directories. If this is not set then the value of **RecommendedVersions**
1864 is used. When this is set then **VersioningAuthoritativeDirectory** should
1867 [[BridgeAuthoritativeDir]] **BridgeAuthoritativeDir** **0**|**1**::
1868 When this option is set in addition to **AuthoritativeDirectory**, Tor
1869 accepts and serves router descriptors, but it caches and serves the main
1870 networkstatus documents rather than generating its own. (Default: 0)
1872 [[MinUptimeHidServDirectoryV2]] **MinUptimeHidServDirectoryV2** __N__ **seconds**|**minutes**|**hours**|**days**|**weeks**::
1873 Minimum uptime of a v2 hidden service directory to be accepted as such by
1874 authoritative directories. (Default: 25 hours)
1876 [[RecommendedServerVersions]] **RecommendedServerVersions** __STRING__::
1877 STRING is a comma-separated list of Tor versions currently believed to be
1878 safe for servers to use. This information is included in version 2
1879 directories. If this is not set then the value of **RecommendedVersions**
1880 is used. When this is set then **VersioningAuthoritativeDirectory** should
1883 [[ConsensusParams]] **ConsensusParams** __STRING__::
1884 STRING is a space-separated list of key=value pairs that Tor will include
1885 in the "params" line of its networkstatus vote.
1887 [[DirAllowPrivateAddresses]] **DirAllowPrivateAddresses** **0**|**1**::
1888 If set to 1, Tor will accept router descriptors with arbitrary "Address"
1889 elements. Otherwise, if the address is not an IP address or is a private IP
1890 address, it will reject the router descriptor. (Default: 0)
1892 [[AuthDirBadDir]] **AuthDirBadDir** __AddressPattern...__::
1893 Authoritative directories only. A set of address patterns for servers that
1894 will be listed as bad directories in any network status document this
1895 authority publishes, if **AuthDirListBadDirs** is set. +
1897 (The address pattern syntax here and in the options below
1898 is the same as for exit policies, except that you don't need to say
1899 "accept" or "reject", and ports are not needed.)
1901 [[AuthDirBadExit]] **AuthDirBadExit** __AddressPattern...__::
1902 Authoritative directories only. A set of address patterns for servers that
1903 will be listed as bad exits in any network status document this authority
1904 publishes, if **AuthDirListBadExits** is set.
1906 [[AuthDirInvalid]] **AuthDirInvalid** __AddressPattern...__::
1907 Authoritative directories only. A set of address patterns for servers that
1908 will never be listed as "valid" in any network status document that this
1909 authority publishes.
1911 [[AuthDirReject]] **AuthDirReject** __AddressPattern__...::
1912 Authoritative directories only. A set of address patterns for servers that
1913 will never be listed at all in any network status document that this
1914 authority publishes, or accepted as an OR address in any descriptor
1915 submitted for publication by this authority.
1917 [[AuthDirBadDirCCs]] **AuthDirBadDirCCs** __CC__,... +
1919 [[AuthDirBadExitCCs]] **AuthDirBadExitCCs** __CC__,... +
1921 [[AuthDirInvalidCCs]] **AuthDirInvalidCCs** __CC__,... +
1923 [[AuthDirRejectCCs]] **AuthDirRejectCCs** __CC__,...::
1924 Authoritative directories only. These options contain a comma-separated
1925 list of country codes such that any server in one of those country codes
1926 will be marked as a bad directory/bad exit/invalid for use, or rejected
1929 [[AuthDirListBadDirs]] **AuthDirListBadDirs** **0**|**1**::
1930 Authoritative directories only. If set to 1, this directory has some
1931 opinion about which nodes are unsuitable as directory caches. (Do not set
1932 this to 1 unless you plan to list non-functioning directories as bad;
1933 otherwise, you are effectively voting in favor of every declared
1936 [[AuthDirListBadExits]] **AuthDirListBadExits** **0**|**1**::
1937 Authoritative directories only. If set to 1, this directory has some
1938 opinion about which nodes are unsuitable as exit nodes. (Do not set this to
1939 1 unless you plan to list non-functioning exits as bad; otherwise, you are
1940 effectively voting in favor of every declared exit as an exit.)
1942 [[AuthDirRejectUnlisted]] **AuthDirRejectUnlisted** **0**|**1**::
1943 Authoritative directories only. If set to 1, the directory server rejects
1944 all uploaded server descriptors that aren't explicitly listed in the
1945 fingerprints file. This acts as a "panic button" if we get hit with a Sybil
1946 attack. (Default: 0)
1948 [[AuthDirMaxServersPerAddr]] **AuthDirMaxServersPerAddr** __NUM__::
1949 Authoritative directories only. The maximum number of servers that we will
1950 list as acceptable on a single IP address. Set this to "0" for "no limit".
1953 [[AuthDirMaxServersPerAuthAddr]] **AuthDirMaxServersPerAuthAddr** __NUM__::
1954 Authoritative directories only. Like AuthDirMaxServersPerAddr, but applies
1955 to addresses shared with directory authorities. (Default: 5)
1957 [[AuthDirFastGuarantee]] **AuthDirFastGuarantee** __N__ **bytes**|**KBytes**|**MBytes**|**GBytes**|**KBits**|**MBits**|**GBits**::
1958 Authoritative directories only. If non-zero, always vote the
1959 Fast flag for any relay advertising this amount of capacity or
1960 more. (Default: 100 KBytes)
1962 [[AuthDirGuardBWGuarantee]] **AuthDirGuardBWGuarantee** __N__ **bytes**|**KBytes**|**MBytes**|**GBytes**|**KBits**|**MBits**|**GBits**::
1963 Authoritative directories only. If non-zero, this advertised capacity
1964 or more is always sufficient to satisfy the bandwidth requirement
1965 for the Guard flag. (Default: 250 KBytes)
1967 [[BridgePassword]] **BridgePassword** __Password__::
1968 If set, contains an HTTP authenticator that tells a bridge authority to
1969 serve all requested bridge information. Used by the (only partially
1970 implemented) "bridge community" design, where a community of bridge
1971 relay operators all use an alternate bridge directory authority,
1972 and their target user audience can periodically fetch the list of
1973 available community bridges to stay up-to-date. (Default: not set)
1975 [[V3AuthVotingInterval]] **V3AuthVotingInterval** __N__ **minutes**|**hours**::
1976 V3 authoritative directories only. Configures the server's preferred voting
1977 interval. Note that voting will __actually__ happen at an interval chosen
1978 by consensus from all the authorities' preferred intervals. This time
1979 SHOULD divide evenly into a day. (Default: 1 hour)
1981 [[V3AuthVoteDelay]] **V3AuthVoteDelay** __N__ **minutes**|**hours**::
1982 V3 authoritative directories only. Configures the server's preferred delay
1983 between publishing its vote and assuming it has all the votes from all the
1984 other authorities. Note that the actual time used is not the server's
1985 preferred time, but the consensus of all preferences. (Default: 5 minutes)
1987 [[V3AuthDistDelay]] **V3AuthDistDelay** __N__ **minutes**|**hours**::
1988 V3 authoritative directories only. Configures the server's preferred delay
1989 between publishing its consensus and signature and assuming it has all the
1990 signatures from all the other authorities. Note that the actual time used
1991 is not the server's preferred time, but the consensus of all preferences.
1992 (Default: 5 minutes)
1994 [[V3AuthNIntervalsValid]] **V3AuthNIntervalsValid** __NUM__::
1995 V3 authoritative directories only. Configures the number of VotingIntervals
1996 for which each consensus should be valid for. Choosing high numbers
1997 increases network partitioning risks; choosing low numbers increases
1998 directory traffic. Note that the actual number of intervals used is not the
1999 server's preferred number, but the consensus of all preferences. Must be at
2000 least 2. (Default: 3)
2002 [[V3BandwidthsFile]] **V3BandwidthsFile** __FILENAME__::
2003 V3 authoritative directories only. Configures the location of the
2004 bandwidth-authority generated file storing information on relays' measured
2005 bandwidth capacities. (Default: unset)
2007 [[V3AuthUseLegacyKey]] **V3AuthUseLegacyKey** **0**|**1**::
2008 If set, the directory authority will sign consensuses not only with its
2009 own signing key, but also with a "legacy" key and certificate with a
2010 different identity. This feature is used to migrate directory authority
2011 keys in the event of a compromise. (Default: 0)
2013 [[RephistTrackTime]] **RephistTrackTime** __N__ **seconds**|**minutes**|**hours**|**days**|**weeks**::
2014 Tells an authority, or other node tracking node reliability and history,
2015 that fine-grained information about nodes can be discarded when it hasn't
2016 changed for a given amount of time. (Default: 24 hours)
2018 [[VoteOnHidServDirectoriesV2]] **VoteOnHidServDirectoriesV2** **0**|**1**::
2019 When this option is set in addition to **AuthoritativeDirectory**, Tor
2020 votes on whether to accept relays as hidden service directories.
2023 [[AuthDirHasIPv6Connectivity]] **AuthDirHasIPv6Connectivity** **0**|**1**::
2024 Authoritative directories only. When set to 0, OR ports with an
2025 IPv6 address are being accepted without reachability testing.
2026 When set to 1, IPv6 OR ports are being tested just like IPv4 OR
2029 [[MinMeasuredBWsForAuthToIgnoreAdvertised]] **MinMeasuredBWsForAuthToIgnoreAdvertised** __N__::
2030 A total value, in abstract bandwidth units, describing how much
2031 measured total bandwidth an authority should have observed on the network
2032 before it will treat advertised bandwidths as wholly
2033 unreliable. (Default: 500)
2035 HIDDEN SERVICE OPTIONS
2036 ----------------------
2038 The following options are used to configure a hidden service.
2040 [[HiddenServiceDir]] **HiddenServiceDir** __DIRECTORY__::
2041 Store data files for a hidden service in DIRECTORY. Every hidden service
2042 must have a separate directory. You may use this option multiple times to
2043 specify multiple services. DIRECTORY must be an existing directory.
2045 [[HiddenServicePort]] **HiddenServicePort** __VIRTPORT__ [__TARGET__]::
2046 Configure a virtual port VIRTPORT for a hidden service. You may use this
2047 option multiple times; each time applies to the service using the most
2048 recent hiddenservicedir. By default, this option maps the virtual port to
2049 the same port on 127.0.0.1 over TCP. You may override the target port,
2050 address, or both by specifying a target of addr, port, or addr:port.
2051 You may also have multiple lines with the same VIRTPORT: when a user
2052 connects to that VIRTPORT, one of the TARGETs from those lines will be
2055 [[PublishHidServDescriptors]] **PublishHidServDescriptors** **0**|**1**::
2056 If set to 0, Tor will run any hidden services you configure, but it won't
2057 advertise them to the rendezvous directory. This option is only useful if
2058 you're using a Tor controller that handles hidserv publishing for you.
2061 [[HiddenServiceVersion]] **HiddenServiceVersion** __version__,__version__,__...__::
2062 A list of rendezvous service descriptor versions to publish for the hidden
2063 service. Currently, only version 2 is supported. (Default: 2)
2065 [[HiddenServiceAuthorizeClient]] **HiddenServiceAuthorizeClient** __auth-type__ __client-name__,__client-name__,__...__::
2066 If configured, the hidden service is accessible for authorized clients
2067 only. The auth-type can either be \'basic' for a general-purpose
2068 authorization protocol or \'stealth' for a less scalable protocol that also
2069 hides service activity from unauthorized clients. Only clients that are
2070 listed here are authorized to access the hidden service. Valid client names
2071 are 1 to 16 characters long and only use characters in A-Za-z0-9+-_ (no
2072 spaces). If this option is set, the hidden service is not accessible for
2073 clients without authorization any more. Generated authorization data can be
2074 found in the hostname file. Clients need to put this authorization data in
2075 their configuration file using **HidServAuth**.
2077 [[RendPostPeriod]] **RendPostPeriod** __N__ **seconds**|**minutes**|**hours**|**days**|**weeks**::
2078 Every time the specified period elapses, Tor uploads any rendezvous
2079 service descriptors to the directory servers. This information is also
2080 uploaded whenever it changes. (Default: 1 hour)
2082 TESTING NETWORK OPTIONS
2083 -----------------------
2085 The following options are used for running a testing Tor network.
2087 [[TestingTorNetwork]] **TestingTorNetwork** **0**|**1**::
2088 If set to 1, Tor adjusts default values of the configuration options below,
2089 so that it is easier to set up a testing Tor network. May only be set if
2090 non-default set of DirAuthorities is set. Cannot be unset while Tor is
2094 ServerDNSAllowBrokenConfig 1
2095 DirAllowPrivateAddresses 1
2096 EnforceDistinctSubnets 0
2098 AuthDirMaxServersPerAddr 0
2099 AuthDirMaxServersPerAuthAddr 0
2100 ClientDNSRejectInternalAddresses 0
2101 ClientRejectInternalAddresses 0
2102 CountPrivateBandwidth 1
2103 ExitPolicyRejectPrivate 0
2104 ExtendAllowPrivateAddresses 1
2105 V3AuthVotingInterval 5 minutes
2106 V3AuthVoteDelay 20 seconds
2107 V3AuthDistDelay 20 seconds
2108 MinUptimeHidServDirectoryV2 0 seconds
2109 TestingV3AuthInitialVotingInterval 5 minutes
2110 TestingV3AuthInitialVoteDelay 20 seconds
2111 TestingV3AuthInitialDistDelay 20 seconds
2112 TestingAuthDirTimeToLearnReachability 0 minutes
2113 TestingEstimatedDescriptorPropagationTime 0 minutes
2114 TestingServerDownloadSchedule 0, 0, 0, 5, 10, 15, 20, 30, 60
2115 TestingClientDownloadSchedule 0, 0, 5, 10, 15, 20, 30, 60
2116 TestingServerConsensusDownloadSchedule 0, 0, 5, 10, 15, 20, 30, 60
2117 TestingClientConsensusDownloadSchedule 0, 0, 5, 10, 15, 20, 30, 60
2118 TestingBridgeDownloadSchedule 60, 30, 30, 60
2119 TestingClientMaxIntervalWithoutRequest 5 seconds
2120 TestingDirConnectionMaxStall 30 seconds
2121 TestingConsensusMaxDownloadTries 80
2122 TestingDescriptorMaxDownloadTries 80
2123 TestingMicrodescMaxDownloadTries 80
2124 TestingCertMaxDownloadTries 80
2125 TestingEnableConnBwEvent 1
2126 TestingEnableCellStatsEvent 1
2127 TestingEnableTbEmptyEvent 1
2129 [[TestingV3AuthInitialVotingInterval]] **TestingV3AuthInitialVotingInterval** __N__ **minutes**|**hours**::
2130 Like V3AuthVotingInterval, but for initial voting interval before the first
2131 consensus has been created. Changing this requires that
2132 **TestingTorNetwork** is set. (Default: 30 minutes)
2134 [[TestingV3AuthInitialVoteDelay]] **TestingV3AuthInitialVoteDelay** __N__ **minutes**|**hours**::
2135 Like V3AuthVoteDelay, but for initial voting interval before
2136 the first consensus has been created. Changing this requires that
2137 **TestingTorNetwork** is set. (Default: 5 minutes)
2139 [[TestingV3AuthInitialDistDelay]] **TestingV3AuthInitialDistDelay** __N__ **minutes**|**hours**::
2140 Like V3AuthDistDelay, but for initial voting interval before
2141 the first consensus has been created. Changing this requires that
2142 **TestingTorNetwork** is set. (Default: 5 minutes)
2144 [[TestingV3AuthVotingStartOffset]] **TestingV3AuthVotingStartOffset** __N__ **seconds**|**minutes**|**hours**::
2145 Directory authorities offset voting start time by this much.
2146 Changing this requires that **TestingTorNetwork** is set. (Default: 0)
2148 [[TestingAuthDirTimeToLearnReachability]] **TestingAuthDirTimeToLearnReachability** __N__ **minutes**|**hours**::
2149 After starting as an authority, do not make claims about whether routers
2150 are Running until this much time has passed. Changing this requires
2151 that **TestingTorNetwork** is set. (Default: 30 minutes)
2153 [[TestingEstimatedDescriptorPropagationTime]] **TestingEstimatedDescriptorPropagationTime** __N__ **minutes**|**hours**::
2154 Clients try downloading router descriptors from directory caches after this
2155 time. Changing this requires that **TestingTorNetwork** is set. (Default:
2158 [[TestingMinFastFlagThreshold]] **TestingMinFastFlagThreshold** __N__ **bytes**|**KBytes**|**MBytes**|**GBytes**|**KBits**|**MBits**|**GBits**::
2159 Minimum value for the Fast flag. Overrides the ordinary minimum taken
2160 from the consensus when TestingTorNetwork is set. (Default: 0.)
2162 [[TestingServerDownloadSchedule]] **TestingServerDownloadSchedule** __N__,__N__,__...__::
2163 Schedule for when servers should download things in general. Changing this
2164 requires that **TestingTorNetwork** is set. (Default: 0, 0, 0, 60, 60, 120,
2165 300, 900, 2147483647)
2167 [[TestingClientDownloadSchedule]] **TestingClientDownloadSchedule** __N__,__N__,__...__::
2168 Schedule for when clients should download things in general. Changing this
2169 requires that **TestingTorNetwork** is set. (Default: 0, 0, 60, 300, 600,
2172 [[TestingServerConsensusDownloadSchedule]] **TestingServerConsensusDownloadSchedule** __N__,__N__,__...__::
2173 Schedule for when servers should download consensuses. Changing this
2174 requires that **TestingTorNetwork** is set. (Default: 0, 0, 60, 300, 600,
2175 1800, 1800, 1800, 1800, 1800, 3600, 7200)
2177 [[TestingClientConsensusDownloadSchedule]] **TestingClientConsensusDownloadSchedule** __N__,__N__,__...__::
2178 Schedule for when clients should download consensuses. Changing this
2179 requires that **TestingTorNetwork** is set. (Default: 0, 0, 60, 300, 600,
2180 1800, 3600, 3600, 3600, 10800, 21600, 43200)
2182 [[TestingBridgeDownloadSchedule]] **TestingBridgeDownloadSchedule** __N__,__N__,__...__::
2183 Schedule for when clients should download bridge descriptors. Changing this
2184 requires that **TestingTorNetwork** is set. (Default: 3600, 900, 900, 3600)
2186 [[TestingClientMaxIntervalWithoutRequest]] **TestingClientMaxIntervalWithoutRequest** __N__ **seconds**|**minutes**::
2187 When directory clients have only a few descriptors to request, they batch
2188 them until they have more, or until this amount of time has passed.
2189 Changing this requires that **TestingTorNetwork** is set. (Default: 10
2192 [[TestingDirConnectionMaxStall]] **TestingDirConnectionMaxStall** __N__ **seconds**|**minutes**::
2193 Let a directory connection stall this long before expiring it.
2194 Changing this requires that **TestingTorNetwork** is set. (Default:
2197 [[TestingConsensusMaxDownloadTries]] **TestingConsensusMaxDownloadTries** __NUM__::
2198 Try this often to download a consensus before giving up. Changing
2199 this requires that **TestingTorNetwork** is set. (Default: 8)
2201 [[TestingDescriptorMaxDownloadTries]] **TestingDescriptorMaxDownloadTries** __NUM__::
2202 Try this often to download a router descriptor before giving up.
2203 Changing this requires that **TestingTorNetwork** is set. (Default: 8)
2205 [[TestingMicrodescMaxDownloadTries]] **TestingMicrodescMaxDownloadTries** __NUM__::
2206 Try this often to download a microdesc descriptor before giving up.
2207 Changing this requires that **TestingTorNetwork** is set. (Default: 8)
2209 [[TestingCertMaxDownloadTries]] **TestingCertMaxDownloadTries** __NUM__::
2210 Try this often to download a v3 authority certificate before giving up.
2211 Changing this requires that **TestingTorNetwork** is set. (Default: 8)
2213 [[TestingDirAuthVoteGuard]] **TestingDirAuthVoteGuard** __node__,__node__,__...__::
2214 A list of identity fingerprints, nicknames, country codes and
2215 address patterns of nodes to vote Guard for regardless of their
2216 uptime and bandwidth. See the **ExcludeNodes** option for more
2217 information on how to specify nodes.
2219 In order for this option to have any effect, **TestingTorNetwork**
2222 [[TestingEnableConnBwEvent]] **TestingEnableConnBwEvent** **0**|**1**::
2223 If this option is set, then Tor controllers may register for CONN_BW
2224 events. Changing this requires that **TestingTorNetwork** is set.
2227 [[TestingEnableCellStatsEvent]] **TestingEnableCellStatsEvent** **0**|**1**::
2228 If this option is set, then Tor controllers may register for CELL_STATS
2229 events. Changing this requires that **TestingTorNetwork** is set.
2232 [[TestingEnableTbEmptyEvent]] **TestingEnableTbEmptyEvent** **0**|**1**::
2233 If this option is set, then Tor controllers may register for TB_EMPTY
2234 events. Changing this requires that **TestingTorNetwork** is set.
2237 [[TestingMinExitFlagThreshold]] **TestingMinExitFlagThreshold** __N__ **KBytes**|**MBytes**|**GBytes**|**KBits**|**MBits**|**GBits**::
2238 Sets a lower-bound for assigning an exit flag when running as an
2239 authority on a testing network. Overrides the usual default lower bound
2240 of 4 KB. (Default: 0)
2245 Tor catches the following signals:
2247 [[SIGTERM]] **SIGTERM**::
2248 Tor will catch this, clean up and sync to disk if necessary, and exit.
2250 [[SIGINT]] **SIGINT**::
2251 Tor clients behave as with SIGTERM; but Tor servers will do a controlled
2252 slow shutdown, closing listeners and waiting 30 seconds before exiting.
2253 (The delay can be configured with the ShutdownWaitLength config option.)
2255 [[SIGHUP]] **SIGHUP**::
2256 The signal instructs Tor to reload its configuration (including closing and
2257 reopening logs), and kill and restart its helper processes if applicable.
2259 [[SIGUSR1]] **SIGUSR1**::
2260 Log statistics about current connections, past connections, and throughput.
2262 [[SIGUSR2]] **SIGUSR2**::
2263 Switch all logs to loglevel debug. You can go back to the old loglevels by
2266 [[SIGCHLD]] **SIGCHLD**::
2267 Tor receives this signal when one of its helper processes has exited, so it
2270 [[SIGPIPE]] **SIGPIPE**::
2271 Tor catches this signal and ignores it.
2273 [[SIGXFSZ]] **SIGXFSZ**::
2274 If this signal exists on your platform, Tor catches and ignores it.
2279 **@CONFDIR@/torrc**::
2280 The configuration file, which contains "option value" pairs.
2283 Fallback location for torrc, if @CONFDIR@/torrc is not found.
2285 **@LOCALSTATEDIR@/lib/tor/**::
2286 The tor process stores keys and other data here.
2288 __DataDirectory__**/cached-status/**::
2289 The most recently downloaded network status document for each authority.
2290 Each file holds one such document; the filenames are the hexadecimal
2291 identity key fingerprints of the directory authorities. Mostly obsolete.
2293 __DataDirectory__**/cached-certs**::
2294 This file holds downloaded directory key certificates that are used to
2295 verify authenticity of documents generated by Tor directory authorities.
2297 __DataDirectory__**/cached-consensus** and/or **cached-microdesc-consensus**::
2298 The most recent consensus network status document we've downloaded.
2300 __DataDirectory__**/cached-descriptors** and **cached-descriptors.new**::
2301 These files hold downloaded router statuses. Some routers may appear more
2302 than once; if so, the most recently published descriptor is used. Lines
2303 beginning with @-signs are annotations that contain more information about
2304 a given router. The ".new" file is an append-only journal; when it gets
2305 too large, all entries are merged into a new cached-descriptors file.
2307 __DataDirectory__**/cached-microdescs** and **cached-microdescs.new**::
2308 These files hold downloaded microdescriptors. Lines beginning with
2309 @-signs are annotations that contain more information about a given
2310 router. The ".new" file is an append-only journal; when it gets too
2311 large, all entries are merged into a new cached-microdescs file.
2313 __DataDirectory__**/cached-routers** and **cached-routers.new**::
2314 Obsolete versions of cached-descriptors and cached-descriptors.new. When
2315 Tor can't find the newer files, it looks here instead.
2317 __DataDirectory__**/state**::
2318 A set of persistent key-value mappings. These are documented in
2319 the file. These include:
2320 - The current entry guards and their status.
2321 - The current bandwidth accounting values (unused so far; see
2323 - When the file was last written
2324 - What version of Tor generated the state file
2325 - A short history of bandwidth usage, as produced in the router
2328 __DataDirectory__**/bw_accounting**::
2329 Used to track bandwidth accounting values (when the current period starts
2330 and ends; how much has been read and written so far this period). This file
2331 is obsolete, and the data is now stored in the \'state' file as well. Only
2332 used when bandwidth accounting is enabled.
2334 __DataDirectory__**/control_auth_cookie**::
2335 Used for cookie authentication with the controller. Location can be
2336 overridden by the CookieAuthFile config option. Regenerated on startup. See
2337 control-spec.txt for details. Only used when cookie authentication is
2340 __DataDirectory__**/lock**::
2341 This file is used to prevent two Tor instances from using same data
2342 directory. If access to this file is locked, data directory is already
2345 __DataDirectory__**/keys/***::
2346 Only used by servers. Holds identity keys and onion keys.
2348 __DataDirectory__**/fingerprint**::
2349 Only used by servers. Holds the fingerprint of the server's identity key.
2351 __DataDirectory__**/hashed-fingerprint**::
2352 Only used by bridges. Holds the hashed fingerprint of the bridge's
2353 identity key. (That is, the hash of the hash of the identity key.)
2355 __DataDirectory__**/approved-routers**::
2356 Only for naming authoritative directory servers (see
2357 **NamingAuthoritativeDirectory**). This file lists nickname to identity
2358 bindings. Each line lists a nickname and a fingerprint separated by
2359 whitespace. See your **fingerprint** file in the __DataDirectory__ for an
2360 example line. If the nickname is **!reject** then descriptors from the
2361 given identity (fingerprint) are rejected by this server. If it is
2362 **!invalid** then descriptors are accepted but marked in the directory as
2363 not valid, that is, not recommended.
2365 __DataDirectory__**/v3-status-votes**::
2366 Only for authoritative directory servers. This file contains status votes
2367 from all the authoritative directory servers and is used to generate the
2368 network consensus document.
2370 __DataDirectory__**/unverified-consensus**::
2371 This file contains a network consensus document that has been downloaded,
2372 but which we didn't have the right certificates to check yet.
2374 __DataDirectory__**/unverified-microdesc-consensus**::
2375 This file contains a microdescriptor-flavored network consensus document
2376 that has been downloaded, but which we didn't have the right certificates
2379 __DataDirectory__**/unparseable-desc**::
2380 Onion router descriptors that Tor was unable to parse are dumped to this
2381 file. Only used for debugging.
2383 __DataDirectory__**/router-stability**::
2384 Only used by authoritative directory servers. Tracks measurements for
2385 router mean-time-between-failures so that authorities have a good idea of
2386 how to set their Stable flags.
2388 __DataDirectory__**/stats/dirreq-stats**::
2389 Only used by directory caches and authorities. This file is used to
2390 collect directory request statistics.
2392 __DataDirectory__**/stats/entry-stats**::
2393 Only used by servers. This file is used to collect incoming connection
2394 statistics by Tor entry nodes.
2396 __DataDirectory__**/stats/bridge-stats**::
2397 Only used by servers. This file is used to collect incoming connection
2398 statistics by Tor bridges.
2400 __DataDirectory__**/stats/exit-stats**::
2401 Only used by servers. This file is used to collect outgoing connection
2402 statistics by Tor exit routers.
2404 __DataDirectory__**/stats/buffer-stats**::
2405 Only used by servers. This file is used to collect buffer usage
2408 __DataDirectory__**/stats/conn-stats**::
2409 Only used by servers. This file is used to collect approximate connection
2410 history (number of active connections over time).
2412 __HiddenServiceDirectory__**/hostname**::
2413 The <base32-encoded-fingerprint>.onion domain name for this hidden service.
2414 If the hidden service is restricted to authorized clients only, this file
2415 also contains authorization data for all clients.
2417 __HiddenServiceDirectory__**/private_key**::
2418 The private key for this hidden service.
2420 __HiddenServiceDirectory__**/client_keys**::
2421 Authorization data for a hidden service that is only accessible by
2426 **torsocks**(1), **torify**(1) +
2428 **https://www.torproject.org/**
2434 Plenty, probably. Tor is still in development. Please report them.
2438 Roger Dingledine [arma at mit.edu], Nick Mathewson [nickm at alum.mit.edu].