summaryrefslogtreecommitdiff
path: root/ssh_config.0
diff options
context:
space:
mode:
Diffstat (limited to 'ssh_config.0')
-rw-r--r--ssh_config.0676
1 files changed, 676 insertions, 0 deletions
diff --git a/ssh_config.0 b/ssh_config.0
new file mode 100644
index 000000000..48969a22a
--- /dev/null
+++ b/ssh_config.0
@@ -0,0 +1,676 @@
1SSH_CONFIG(5) OpenBSD Programmer's Manual SSH_CONFIG(5)
2
3NAME
4 ssh_config - OpenSSH SSH client configuration files
5
6SYNOPSIS
7 ~/.ssh/config
8 /etc/ssh/ssh_config
9
10DESCRIPTION
11 ssh(1) obtains configuration data from the following sources in the fol-
12 lowing order:
13
14 1. command-line options
15 2. user's configuration file (~/.ssh/config)
16 3. system-wide configuration file (/etc/ssh/ssh_config)
17
18 For each parameter, the first obtained value will be used. The configu-
19 ration files contain sections separated by ``Host'' specifications, and
20 that section is only applied for hosts that match one of the patterns
21 given in the specification. The matched host name is the one given on
22 the command line.
23
24 Since the first obtained value for each parameter is used, more host-spe-
25 cific declarations should be given near the beginning of the file, and
26 general defaults at the end.
27
28 The configuration file has the following format:
29
30 Empty lines and lines starting with `#' are comments. Otherwise a line
31 is of the format ``keyword arguments''. Configuration options may be
32 separated by whitespace or optional whitespace and exactly one `='; the
33 latter format is useful to avoid the need to quote whitespace when speci-
34 fying configuration options using the ssh, scp, and sftp -o option. Ar-
35 guments may optionally be enclosed in double quotes (") in order to rep-
36 resent arguments containing spaces.
37
38 The possible keywords and their meanings are as follows (note that key-
39 words are case-insensitive and arguments are case-sensitive):
40
41 Host Restricts the following declarations (up to the next Host key-
42 word) to be only for those hosts that match one of the patterns
43 given after the keyword. If more than one pattern is provided,
44 they should be separated by whitespace. A single `*' as a pat-
45 tern can be used to provide global defaults for all hosts. The
46 host is the hostname argument given on the command line (i.e. the
47 name is not converted to a canonicalized host name before match-
48 ing).
49
50 See PATTERNS for more information on patterns.
51
52 AddressFamily
53 Specifies which address family to use when connecting. Valid ar-
54 guments are ``any'', ``inet'' (use IPv4 only), or ``inet6'' (use
55 IPv6 only).
56
57 BatchMode
58 If set to ``yes'', passphrase/password querying will be disabled.
59 This option is useful in scripts and other batch jobs where no
60 user is present to supply the password. The argument must be
61 ``yes'' or ``no''. The default is ``no''.
62
63 BindAddress
64 Use the specified address on the local machine as the source ad-
65 dress of the connection. Only useful on systems with more than
66 one address. Note that this option does not work if
67 UsePrivilegedPort is set to ``yes''.
68
69 ChallengeResponseAuthentication
70 Specifies whether to use challenge-response authentication. The
71 argument to this keyword must be ``yes'' or ``no''. The default
72 is ``yes''.
73
74 CheckHostIP
75 If this flag is set to ``yes'', ssh(1) will additionally check
76 the host IP address in the known_hosts file. This allows ssh to
77 detect if a host key changed due to DNS spoofing. If the option
78 is set to ``no'', the check will not be executed. The default is
79 ``yes''.
80
81 Cipher Specifies the cipher to use for encrypting the session in proto-
82 col version 1. Currently, ``blowfish'', ``3des'', and ``des''
83 are supported. des is only supported in the ssh(1) client for
84 interoperability with legacy protocol 1 implementations that do
85 not support the 3des cipher. Its use is strongly discouraged due
86 to cryptographic weaknesses. The default is ``3des''.
87
88 Ciphers
89 Specifies the ciphers allowed for protocol version 2 in order of
90 preference. Multiple ciphers must be comma-separated. The sup-
91 ported ciphers are ``3des-cbc'', ``aes128-cbc'', ``aes192-cbc'',
92 ``aes256-cbc'', ``aes128-ctr'', ``aes192-ctr'', ``aes256-ctr'',
93 ``arcfour128'', ``arcfour256'', ``arcfour'', ``blowfish-cbc'',
94 and ``cast128-cbc''. The default is:
95
96 aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,
97 aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,
98 aes256-cbc,arcfour
99
100 ClearAllForwardings
101 Specifies that all local, remote, and dynamic port forwardings
102 specified in the configuration files or on the command line be
103 cleared. This option is primarily useful when used from the
104 ssh(1) command line to clear port forwardings set in configura-
105 tion files, and is automatically set by scp(1) and sftp(1). The
106 argument must be ``yes'' or ``no''. The default is ``no''.
107
108 Compression
109 Specifies whether to use compression. The argument must be
110 ``yes'' or ``no''. The default is ``no''.
111
112 CompressionLevel
113 Specifies the compression level to use if compression is enabled.
114 The argument must be an integer from 1 (fast) to 9 (slow, best).
115 The default level is 6, which is good for most applications. The
116 meaning of the values is the same as in gzip(1). Note that this
117 option applies to protocol version 1 only.
118
119 ConnectionAttempts
120 Specifies the number of tries (one per second) to make before ex-
121 iting. The argument must be an integer. This may be useful in
122 scripts if the connection sometimes fails. The default is 1.
123
124 ConnectTimeout
125 Specifies the timeout (in seconds) used when connecting to the
126 SSH server, instead of using the default system TCP timeout.
127 This value is used only when the target is down or really un-
128 reachable, not when it refuses the connection.
129
130 ControlMaster
131 Enables the sharing of multiple sessions over a single network
132 connection. When set to ``yes'', ssh(1) will listen for connec-
133 tions on a control socket specified using the ControlPath argu-
134 ment. Additional sessions can connect to this socket using the
135 same ControlPath with ControlMaster set to ``no'' (the default).
136 These sessions will try to reuse the master instance's network
137 connection rather than initiating new ones, but will fall back to
138 connecting normally if the control socket does not exist, or is
139 not listening.
140
141 Setting this to ``ask'' will cause ssh to listen for control con-
142 nections, but require confirmation using the SSH_ASKPASS program
143 before they are accepted (see ssh-add(1) for details). If the
144 ControlPath cannot be opened, ssh will continue without connect-
145 ing to a master instance.
146
147 X11 and ssh-agent(1) forwarding is supported over these multi-
148 plexed connections, however the display and agent forwarded will
149 be the one belonging to the master connection i.e. it is not pos-
150 sible to forward multiple displays or agents.
151
152 Two additional options allow for opportunistic multiplexing: try
153 to use a master connection but fall back to creating a new one if
154 one does not already exist. These options are: ``auto'' and
155 ``autoask''. The latter requires confirmation like the ``ask''
156 option.
157
158 ControlPath
159 Specify the path to the control socket used for connection shar-
160 ing as described in the ControlMaster section above or the string
161 ``none'' to disable connection sharing. In the path, `%l' will
162 be substituted by the local host name, `%h' will be substituted
163 by the target host name, `%p' the port, and `%r' by the remote
164 login username. It is recommended that any ControlPath used for
165 opportunistic connection sharing include at least %h, %p, and %r.
166 This ensures that shared connections are uniquely identified.
167
168 DynamicForward
169 Specifies that a TCP port on the local machine be forwarded over
170 the secure channel, and the application protocol is then used to
171 determine where to connect to from the remote machine.
172
173 The argument must be [bind_address:]port. IPv6 addresses can be
174 specified by enclosing addresses in square brackets or by using
175 an alternative syntax: [bind_address/]port. By default, the lo-
176 cal port is bound in accordance with the GatewayPorts setting.
177 However, an explicit bind_address may be used to bind the connec-
178 tion to a specific address. The bind_address of ``localhost''
179 indicates that the listening port be bound for local use only,
180 while an empty address or `*' indicates that the port should be
181 available from all interfaces.
182
183 Currently the SOCKS4 and SOCKS5 protocols are supported, and
184 ssh(1) will act as a SOCKS server. Multiple forwardings may be
185 specified, and additional forwardings can be given on the command
186 line. Only the superuser can forward privileged ports.
187
188 EnableSSHKeysign
189 Setting this option to ``yes'' in the global client configuration
190 file /etc/ssh/ssh_config enables the use of the helper program
191 ssh-keysign(8) during HostbasedAuthentication. The argument must
192 be ``yes'' or ``no''. The default is ``no''. This option should
193 be placed in the non-hostspecific section. See ssh-keysign(8)
194 for more information.
195
196 EscapeChar
197 Sets the escape character (default: `~'). The escape character
198 can also be set on the command line. The argument should be a
199 single character, `^' followed by a letter, or ``none'' to dis-
200 able the escape character entirely (making the connection trans-
201 parent for binary data).
202
203 ExitOnForwardFailure
204 Specifies whether ssh(1) should terminate the connection if it
205 cannot set up all requested dynamic, tunnel, local, and remote
206 port forwardings. The argument must be ``yes'' or ``no''. The
207 default is ``no''.
208
209 ForwardAgent
210 Specifies whether the connection to the authentication agent (if
211 any) will be forwarded to the remote machine. The argument must
212 be ``yes'' or ``no''. The default is ``no''.
213
214 Agent forwarding should be enabled with caution. Users with the
215 ability to bypass file permissions on the remote host (for the
216 agent's Unix-domain socket) can access the local agent through
217 the forwarded connection. An attacker cannot obtain key material
218 from the agent, however they can perform operations on the keys
219 that enable them to authenticate using the identities loaded into
220 the agent.
221
222 ForwardX11
223 Specifies whether X11 connections will be automatically redirect-
224 ed over the secure channel and DISPLAY set. The argument must be
225 ``yes'' or ``no''. The default is ``no''.
226
227 X11 forwarding should be enabled with caution. Users with the
228 ability to bypass file permissions on the remote host (for the
229 user's X11 authorization database) can access the local X11 dis-
230 play through the forwarded connection. An attacker may then be
231 able to perform activities such as keystroke monitoring if the
232 ForwardX11Trusted option is also enabled.
233
234 ForwardX11Trusted
235 If this option is set to ``yes'', remote X11 clients will have
236 full access to the original X11 display.
237
238 If this option is set to ``no'', remote X11 clients will be con-
239 sidered untrusted and prevented from stealing or tampering with
240 data belonging to trusted X11 clients. Furthermore, the xauth(1)
241 token used for the session will be set to expire after 20 min-
242 utes. Remote clients will be refused access after this time.
243
244 The default is ``no''.
245
246 See the X11 SECURITY extension specification for full details on
247 the restrictions imposed on untrusted clients.
248
249 GatewayPorts
250 Specifies whether remote hosts are allowed to connect to local
251 forwarded ports. By default, ssh(1) binds local port forwardings
252 to the loopback address. This prevents other remote hosts from
253 connecting to forwarded ports. GatewayPorts can be used to spec-
254 ify that ssh should bind local port forwardings to the wildcard
255 address, thus allowing remote hosts to connect to forwarded
256 ports. The argument must be ``yes'' or ``no''. The default is
257 ``no''.
258
259 GlobalKnownHostsFile
260 Specifies a file to use for the global host key database instead
261 of /etc/ssh/ssh_known_hosts.
262
263 GSSAPIAuthentication
264 Specifies whether user authentication based on GSSAPI is allowed.
265 The default is ``no''. Note that this option applies to protocol
266 version 2 only.
267
268 GSSAPIDelegateCredentials
269 Forward (delegate) credentials to the server. The default is
270 ``no''. Note that this option applies to protocol version 2 on-
271 ly.
272
273 HashKnownHosts
274 Indicates that ssh(1) should hash host names and addresses when
275 they are added to ~/.ssh/known_hosts. These hashed names may be
276 used normally by ssh(1) and sshd(8), but they do not reveal iden-
277 tifying information should the file's contents be disclosed. The
278 default is ``no''. Note that existing names and addresses in
279 known hosts files will not be converted automatically, but may be
280 manually hashed using ssh-keygen(1).
281
282 HostbasedAuthentication
283 Specifies whether to try rhosts based authentication with public
284 key authentication. The argument must be ``yes'' or ``no''. The
285 default is ``no''. This option applies to protocol version 2 on-
286 ly and is similar to RhostsRSAAuthentication.
287
288 HostKeyAlgorithms
289 Specifies the protocol version 2 host key algorithms that the
290 client wants to use in order of preference. The default for this
291 option is: ``ssh-rsa,ssh-dss''.
292
293 HostKeyAlias
294 Specifies an alias that should be used instead of the real host
295 name when looking up or saving the host key in the host key
296 database files. This option is useful for tunneling SSH connec-
297 tions or for multiple servers running on a single host.
298
299 HostName
300 Specifies the real host name to log into. This can be used to
301 specify nicknames or abbreviations for hosts. The default is the
302 name given on the command line. Numeric IP addresses are also
303 permitted (both on the command line and in HostName specifica-
304 tions).
305
306 IdentitiesOnly
307 Specifies that ssh(1) should only use the authentication identity
308 files configured in the ssh_config files, even if ssh-agent(1)
309 offers more identities. The argument to this keyword must be
310 ``yes'' or ``no''. This option is intended for situations where
311 ssh-agent offers many different identities. The default is
312 ``no''.
313
314 IdentityFile
315 Specifies a file from which the user's RSA or DSA authentication
316 identity is read. The default is ~/.ssh/identity for protocol
317 version 1, and ~/.ssh/id_rsa and ~/.ssh/id_dsa for protocol ver-
318 sion 2. Additionally, any identities represented by the authen-
319 tication agent will be used for authentication. ssh(1) will try
320 to load certificate information from the filename obtained by ap-
321 pending -cert.pub to the path of a specified IdentityFile.
322
323 The file name may use the tilde syntax to refer to a user's home
324 directory or one of the following escape characters: `%d' (local
325 user's home directory), `%u' (local user name), `%l' (local host
326 name), `%h' (remote host name) or `%r' (remote user name).
327
328 It is possible to have multiple identity files specified in con-
329 figuration files; all these identities will be tried in sequence.
330
331 KbdInteractiveAuthentication
332 Specifies whether to use keyboard-interactive authentication.
333 The argument to this keyword must be ``yes'' or ``no''. The de-
334 fault is ``yes''.
335
336 KbdInteractiveDevices
337 Specifies the list of methods to use in keyboard-interactive au-
338 thentication. Multiple method names must be comma-separated.
339 The default is to use the server specified list. The methods
340 available vary depending on what the server supports. For an
341 OpenSSH server, it may be zero or more of: ``bsdauth'', ``pam'',
342 and ``skey''.
343
344 LocalCommand
345 Specifies a command to execute on the local machine after suc-
346 cessfully connecting to the server. The command string extends
347 to the end of the line, and is executed with the user's shell.
348 The following escape character substitutions will be performed:
349 `%d' (local user's home directory), `%h' (remote host name), `%l'
350 (local host name), `%n' (host name as provided on the command
351 line), `%p' (remote port), `%r' (remote user name) or `%u' (local
352 user name).
353
354 The command is run synchronously and does not have access to the
355 session of the ssh(1) that spawned it. It should not be used for
356 interactive commands.
357
358 This directive is ignored unless PermitLocalCommand has been en-
359 abled.
360
361 LocalForward
362 Specifies that a TCP port on the local machine be forwarded over
363 the secure channel to the specified host and port from the remote
364 machine. The first argument must be [bind_address:]port and the
365 second argument must be host:hostport. IPv6 addresses can be
366 specified by enclosing addresses in square brackets or by using
367 an alternative syntax: [bind_address/]port and host/hostport.
368 Multiple forwardings may be specified, and additional forwardings
369 can be given on the command line. Only the superuser can forward
370 privileged ports. By default, the local port is bound in accor-
371 dance with the GatewayPorts setting. However, an explicit
372 bind_address may be used to bind the connection to a specific ad-
373 dress. The bind_address of ``localhost'' indicates that the lis-
374 tening port be bound for local use only, while an empty address
375 or `*' indicates that the port should be available from all in-
376 terfaces.
377
378 LogLevel
379 Gives the verbosity level that is used when logging messages from
380 ssh(1). The possible values are: QUIET, FATAL, ERROR, INFO, VER-
381 BOSE, DEBUG, DEBUG1, DEBUG2, and DEBUG3. The default is INFO.
382 DEBUG and DEBUG1 are equivalent. DEBUG2 and DEBUG3 each specify
383 higher levels of verbose output.
384
385 MACs Specifies the MAC (message authentication code) algorithms in or-
386 der of preference. The MAC algorithm is used in protocol version
387 2 for data integrity protection. Multiple algorithms must be
388 comma-separated. The default is:
389
390 hmac-md5,hmac-sha1,umac-64@openssh.com,
391 hmac-ripemd160,hmac-sha1-96,hmac-md5-96
392
393 NoHostAuthenticationForLocalhost
394 This option can be used if the home directory is shared across
395 machines. In this case localhost will refer to a different ma-
396 chine on each of the machines and the user will get many warnings
397 about changed host keys. However, this option disables host au-
398 thentication for localhost. The argument to this keyword must be
399 ``yes'' or ``no''. The default is to check the host key for lo-
400 calhost.
401
402 NumberOfPasswordPrompts
403 Specifies the number of password prompts before giving up. The
404 argument to this keyword must be an integer. The default is 3.
405
406 PasswordAuthentication
407 Specifies whether to use password authentication. The argument
408 to this keyword must be ``yes'' or ``no''. The default is
409 ``yes''.
410
411 PermitLocalCommand
412 Allow local command execution via the LocalCommand option or us-
413 ing the !command escape sequence in ssh(1). The argument must be
414 ``yes'' or ``no''. The default is ``no''.
415
416 PKCS11Provider
417 Specifies which PKCS#11 provider to use. The argument to this
418 keyword is the PKCS#11 shared libary ssh(1) should use to commu-
419 nicate with a PKCS#11 token providing the user's private RSA key.
420
421 Port Specifies the port number to connect on the remote host. The de-
422 fault is 22.
423
424 PreferredAuthentications
425 Specifies the order in which the client should try protocol 2 au-
426 thentication methods. This allows a client to prefer one method
427 (e.g. keyboard-interactive) over another method (e.g. password)
428 The default for this option is: ``gssapi-with-mic,hostbased,
429 publickey, keyboard-interactive, password''.
430
431 Protocol
432 Specifies the protocol versions ssh(1) should support in order of
433 preference. The possible values are `1' and `2'. Multiple ver-
434 sions must be comma-separated. When this option is set to
435 ``2,1'' ssh will try version 2 and fall back to version 1 if ver-
436 sion 2 is not available. The default is `2'.
437
438 ProxyCommand
439 Specifies the command to use to connect to the server. The com-
440 mand string extends to the end of the line, and is executed with
441 the user's shell. In the command string, `%h' will be substitut-
442 ed by the host name to connect and `%p' by the port. The command
443 can be basically anything, and should read from its standard in-
444 put and write to its standard output. It should eventually con-
445 nect an sshd(8) server running on some machine, or execute sshd
446 -i somewhere. Host key management will be done using the Host-
447 Name of the host being connected (defaulting to the name typed by
448 the user). Setting the command to ``none'' disables this option
449 entirely. Note that CheckHostIP is not available for connects
450 with a proxy command.
451
452 This directive is useful in conjunction with nc(1) and its proxy
453 support. For example, the following directive would connect via
454 an HTTP proxy at 192.0.2.0:
455
456 ProxyCommand /usr/bin/nc -X connect -x 192.0.2.0:8080 %h %p
457
458 PubkeyAuthentication
459 Specifies whether to try public key authentication. The argument
460 to this keyword must be ``yes'' or ``no''. The default is
461 ``yes''. This option applies to protocol version 2 only.
462
463 RekeyLimit
464 Specifies the maximum amount of data that may be transmitted be-
465 fore the session key is renegotiated. The argument is the number
466 of bytes, with an optional suffix of `K', `M', or `G' to indicate
467 Kilobytes, Megabytes, or Gigabytes, respectively. The default is
468 between `1G' and `4G', depending on the cipher. This option ap-
469 plies to protocol version 2 only.
470
471 RemoteForward
472 Specifies that a TCP port on the remote machine be forwarded over
473 the secure channel to the specified host and port from the local
474 machine. The first argument must be [bind_address:]port and the
475 second argument must be host:hostport. IPv6 addresses can be
476 specified by enclosing addresses in square brackets or by using
477 an alternative syntax: [bind_address/]port and host/hostport.
478 Multiple forwardings may be specified, and additional forwardings
479 can be given on the command line. Privileged ports can be for-
480 warded only when logging in as root on the remote machine.
481
482 If the port argument is `0', the listen port will be dynamically
483 allocated on the server and reported to the client at run time.
484
485 If the bind_address is not specified, the default is to only bind
486 to loopback addresses. If the bind_address is `*' or an empty
487 string, then the forwarding is requested to listen on all inter-
488 faces. Specifying a remote bind_address will only succeed if the
489 server's GatewayPorts option is enabled (see sshd_config(5)).
490
491 RhostsRSAAuthentication
492 Specifies whether to try rhosts based authentication with RSA
493 host authentication. The argument must be ``yes'' or ``no''.
494 The default is ``no''. This option applies to protocol version 1
495 only and requires ssh(1) to be setuid root.
496
497 RSAAuthentication
498 Specifies whether to try RSA authentication. The argument to
499 this keyword must be ``yes'' or ``no''. RSA authentication will
500 only be attempted if the identity file exists, or an authentica-
501 tion agent is running. The default is ``yes''. Note that this
502 option applies to protocol version 1 only.
503
504 SendEnv
505 Specifies what variables from the local environ(7) should be sent
506 to the server. Note that environment passing is only supported
507 for protocol 2. The server must also support it, and the server
508 must be configured to accept these environment variables. Refer
509 to AcceptEnv in sshd_config(5) for how to configure the server.
510 Variables are specified by name, which may contain wildcard char-
511 acters. Multiple environment variables may be separated by
512 whitespace or spread across multiple SendEnv directives. The de-
513 fault is not to send any environment variables.
514
515 See PATTERNS for more information on patterns.
516
517 ServerAliveCountMax
518 Sets the number of server alive messages (see below) which may be
519 sent without ssh(1) receiving any messages back from the server.
520 If this threshold is reached while server alive messages are be-
521 ing sent, ssh will disconnect from the server, terminating the
522 session. It is important to note that the use of server alive
523 messages is very different from TCPKeepAlive (below). The server
524 alive messages are sent through the encrypted channel and there-
525 fore will not be spoofable. The TCP keepalive option enabled by
526 TCPKeepAlive is spoofable. The server alive mechanism is valu-
527 able when the client or server depend on knowing when a connec-
528 tion has become inactive.
529
530 The default value is 3. If, for example, ServerAliveInterval
531 (see below) is set to 15 and ServerAliveCountMax is left at the
532 default, if the server becomes unresponsive, ssh will disconnect
533 after approximately 45 seconds. This option applies to protocol
534 version 2 only.
535
536 ServerAliveInterval
537 Sets a timeout interval in seconds after which if no data has
538 been received from the server, ssh(1) will send a message through
539 the encrypted channel to request a response from the server. The
540 default is 0, indicating that these messages will not be sent to
541 the server. This option applies to protocol version 2 only.
542
543 StrictHostKeyChecking
544 If this flag is set to ``yes'', ssh(1) will never automatically
545 add host keys to the ~/.ssh/known_hosts file, and refuses to con-
546 nect to hosts whose host key has changed. This provides maximum
547 protection against trojan horse attacks, though it can be annoy-
548 ing when the /etc/ssh/ssh_known_hosts file is poorly maintained
549 or when connections to new hosts are frequently made. This op-
550 tion forces the user to manually add all new hosts. If this flag
551 is set to ``no'', ssh will automatically add new host keys to the
552 user known hosts files. If this flag is set to ``ask'', new host
553 keys will be added to the user known host files only after the
554 user has confirmed that is what they really want to do, and ssh
555 will refuse to connect to hosts whose host key has changed. The
556 host keys of known hosts will be verified automatically in all
557 cases. The argument must be ``yes'', ``no'', or ``ask''. The
558 default is ``ask''.
559
560 TCPKeepAlive
561 Specifies whether the system should send TCP keepalive messages
562 to the other side. If they are sent, death of the connection or
563 crash of one of the machines will be properly noticed. However,
564 this means that connections will die if the route is down tem-
565 porarily, and some people find it annoying.
566
567 The default is ``yes'' (to send TCP keepalive messages), and the
568 client will notice if the network goes down or the remote host
569 dies. This is important in scripts, and many users want it too.
570
571 To disable TCP keepalive messages, the value should be set to
572 ``no''.
573
574 Tunnel Request tun(4) device forwarding between the client and the serv-
575 er. The argument must be ``yes'', ``point-to-point'' (layer 3),
576 ``ethernet'' (layer 2), or ``no''. Specifying ``yes'' requests
577 the default tunnel mode, which is ``point-to-point''. The de-
578 fault is ``no''.
579
580 TunnelDevice
581 Specifies the tun(4) devices to open on the client (local_tun)
582 and the server (remote_tun).
583
584 The argument must be local_tun[:remote_tun]. The devices may be
585 specified by numerical ID or the keyword ``any'', which uses the
586 next available tunnel device. If remote_tun is not specified, it
587 defaults to ``any''. The default is ``any:any''.
588
589 UsePrivilegedPort
590 Specifies whether to use a privileged port for outgoing connec-
591 tions. The argument must be ``yes'' or ``no''. The default is
592 ``no''. If set to ``yes'', ssh(1) must be setuid root. Note
593 that this option must be set to ``yes'' for
594 RhostsRSAAuthentication with older servers.
595
596 User Specifies the user to log in as. This can be useful when a dif-
597 ferent user name is used on different machines. This saves the
598 trouble of having to remember to give the user name on the com-
599 mand line.
600
601 UserKnownHostsFile
602 Specifies a file to use for the user host key database instead of
603 ~/.ssh/known_hosts.
604
605 VerifyHostKeyDNS
606 Specifies whether to verify the remote key using DNS and SSHFP
607 resource records. If this option is set to ``yes'', the client
608 will implicitly trust keys that match a secure fingerprint from
609 DNS. Insecure fingerprints will be handled as if this option was
610 set to ``ask''. If this option is set to ``ask'', information on
611 fingerprint match will be displayed, but the user will still need
612 to confirm new host keys according to the StrictHostKeyChecking
613 option. The argument must be ``yes'', ``no'', or ``ask''. The
614 default is ``no''. Note that this option applies to protocol
615 version 2 only.
616
617 See also VERIFYING HOST KEYS in ssh(1).
618
619 VisualHostKey
620 If this flag is set to ``yes'', an ASCII art representation of
621 the remote host key fingerprint is printed in addition to the hex
622 fingerprint string at login and for unknown host keys. If this
623 flag is set to ``no'', no fingerprint strings are printed at lo-
624 gin and only the hex fingerprint string will be printed for un-
625 known host keys. The default is ``no''.
626
627 XAuthLocation
628 Specifies the full pathname of the xauth(1) program. The default
629 is /usr/X11R6/bin/xauth.
630
631PATTERNS
632 A pattern consists of zero or more non-whitespace characters, `*' (a
633 wildcard that matches zero or more characters), or `?' (a wildcard that
634 matches exactly one character). For example, to specify a set of decla-
635 rations for any host in the ``.co.uk'' set of domains, the following pat-
636 tern could be used:
637
638 Host *.co.uk
639
640 The following pattern would match any host in the 192.168.0.[0-9] network
641 range:
642
643 Host 192.168.0.?
644
645 A pattern-list is a comma-separated list of patterns. Patterns within
646 pattern-lists may be negated by preceding them with an exclamation mark
647 (`!'). For example, to allow a key to be used from anywhere within an
648 organisation except from the ``dialup'' pool, the following entry (in au-
649 thorized_keys) could be used:
650
651 from="!*.dialup.example.com,*.example.com"
652
653FILES
654 ~/.ssh/config
655 This is the per-user configuration file. The format of this file
656 is described above. This file is used by the SSH client. Be-
657 cause of the potential for abuse, this file must have strict per-
658 missions: read/write for the user, and not accessible by others.
659
660 /etc/ssh/ssh_config
661 Systemwide configuration file. This file provides defaults for
662 those values that are not specified in the user's configuration
663 file, and for those users who do not have a configuration file.
664 This file must be world-readable.
665
666SEE ALSO
667 ssh(1)
668
669AUTHORS
670 OpenSSH is a derivative of the original and free ssh 1.2.12 release by
671 Tatu Ylonen. Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, Theo
672 de Raadt and Dug Song removed many bugs, re-added newer features and cre-
673 ated OpenSSH. Markus Friedl contributed the support for SSH protocol
674 versions 1.5 and 2.0.
675
676OpenBSD 4.6 March 5, 2010 11
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-11 03:17:03 +0000