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1SSH_CONFIG(5) File Formats Manual SSH_CONFIG(5)
2
3NAME
4 ssh_config M-bM-^@M-^S OpenSSH client configuration file
5
6DESCRIPTION
7 ssh(1) obtains configuration data from the following sources in the
8 following order:
9
10 1. command-line options
11 2. user's configuration file (~/.ssh/config)
12 3. system-wide configuration file (/etc/ssh/ssh_config)
13
14 For each parameter, the first obtained value will be used. The
15 configuration files contain sections separated by Host specifications,
16 and that section is only applied for hosts that match one of the patterns
17 given in the specification. The matched host name is usually the one
18 given on the command line (see the CanonicalizeHostname option for
19 exceptions).
20
21 Since the first obtained value for each parameter is used, more host-
22 specific declarations should be given near the beginning of the file, and
23 general defaults at the end.
24
25 The file contains keyword-argument pairs, one per line. Lines starting
26 with M-bM-^@M-^X#M-bM-^@M-^Y and empty lines are interpreted as comments. Arguments may
27 optionally be enclosed in double quotes (") in order to represent
28 arguments containing spaces. Configuration options may be separated by
29 whitespace or optional whitespace and exactly one M-bM-^@M-^X=M-bM-^@M-^Y; the latter format
30 is useful to avoid the need to quote whitespace when specifying
31 configuration options using the ssh, scp, and sftp -o option.
32
33 The possible keywords and their meanings are as follows (note that
34 keywords are case-insensitive and arguments are case-sensitive):
35
36 Host Restricts the following declarations (up to the next Host or
37 Match keyword) to be only for those hosts that match one of the
38 patterns given after the keyword. If more than one pattern is
39 provided, they should be separated by whitespace. A single M-bM-^@M-^X*M-bM-^@M-^Y
40 as a pattern can be used to provide global defaults for all
41 hosts. The host is usually the hostname argument given on the
42 command line (see the CanonicalizeHostname keyword for
43 exceptions).
44
45 A pattern entry may be negated by prefixing it with an
46 exclamation mark (M-bM-^@M-^X!M-bM-^@M-^Y). If a negated entry is matched, then the
47 Host entry is ignored, regardless of whether any other patterns
48 on the line match. Negated matches are therefore useful to
49 provide exceptions for wildcard matches.
50
51 See PATTERNS for more information on patterns.
52
53 Match Restricts the following declarations (up to the next Host or
54 Match keyword) to be used only when the conditions following the
55 Match keyword are satisfied. Match conditions are specified
56 using one or more criteria or the single token all which always
57 matches. The available criteria keywords are: canonical, final,
58 exec, host, originalhost, user, and localuser. The all criteria
59 must appear alone or immediately after canonical or final. Other
60 criteria may be combined arbitrarily. All criteria but all,
61 canonical, and final require an argument. Criteria may be
62 negated by prepending an exclamation mark (M-bM-^@M-^X!M-bM-^@M-^Y).
63
64 The canonical keyword matches only when the configuration file is
65 being re-parsed after hostname canonicalization (see the
66 CanonicalizeHostname option). This may be useful to specify
67 conditions that work with canonical host names only.
68
69 The final keyword requests that the configuration be re-parsed
70 (regardless of whether CanonicalizeHostname is enabled), and
71 matches only during this final pass. If CanonicalizeHostname is
72 enabled, then canonical and final match during the same pass.
73
74 The exec keyword executes the specified command under the user's
75 shell. If the command returns a zero exit status then the
76 condition is considered true. Commands containing whitespace
77 characters must be quoted. Arguments to exec accept the tokens
78 described in the TOKENS section.
79
80 The other keywords' criteria must be single entries or comma-
81 separated lists and may use the wildcard and negation operators
82 described in the PATTERNS section. The criteria for the host
83 keyword are matched against the target hostname, after any
84 substitution by the Hostname or CanonicalizeHostname options.
85 The originalhost keyword matches against the hostname as it was
86 specified on the command-line. The user keyword matches against
87 the target username on the remote host. The localuser keyword
88 matches against the name of the local user running ssh(1) (this
89 keyword may be useful in system-wide ssh_config files).
90
91 AddKeysToAgent
92 Specifies whether keys should be automatically added to a running
93 ssh-agent(1). If this option is set to yes and a key is loaded
94 from a file, the key and its passphrase are added to the agent
95 with the default lifetime, as if by ssh-add(1). If this option
96 is set to ask, ssh(1) will require confirmation using the
97 SSH_ASKPASS program before adding a key (see ssh-add(1) for
98 details). If this option is set to confirm, each use of the key
99 must be confirmed, as if the -c option was specified to
100 ssh-add(1). If this option is set to no, no keys are added to
101 the agent. The argument must be yes, confirm, ask, or no (the
102 default).
103
104 AddressFamily
105 Specifies which address family to use when connecting. Valid
106 arguments are any (the default), inet (use IPv4 only), or inet6
107 (use IPv6 only).
108
109 BatchMode
110 If set to yes, user interaction such as password prompts and host
111 key confirmation requests will be disabled. This option is
112 useful in scripts and other batch jobs where no user is present
113 to interact with ssh(1). The argument must be yes or no (the
114 default).
115
116 BindAddress
117 Use the specified address on the local machine as the source
118 address of the connection. Only useful on systems with more than
119 one address.
120
121 BindInterface
122 Use the address of the specified interface on the local machine
123 as the source address of the connection.
124
125 CanonicalDomains
126 When CanonicalizeHostname is enabled, this option specifies the
127 list of domain suffixes in which to search for the specified
128 destination host.
129
130 CanonicalizeFallbackLocal
131 Specifies whether to fail with an error when hostname
132 canonicalization fails. The default, yes, will attempt to look
133 up the unqualified hostname using the system resolver's search
134 rules. A value of no will cause ssh(1) to fail instantly if
135 CanonicalizeHostname is enabled and the target hostname cannot be
136 found in any of the domains specified by CanonicalDomains.
137
138 CanonicalizeHostname
139 Controls whether explicit hostname canonicalization is performed.
140 The default, no, is not to perform any name rewriting and let the
141 system resolver handle all hostname lookups. If set to yes then,
142 for connections that do not use a ProxyCommand or ProxyJump,
143 ssh(1) will attempt to canonicalize the hostname specified on the
144 command line using the CanonicalDomains suffixes and
145 CanonicalizePermittedCNAMEs rules. If CanonicalizeHostname is
146 set to always, then canonicalization is applied to proxied
147 connections too.
148
149 If this option is enabled, then the configuration files are
150 processed again using the new target name to pick up any new
151 configuration in matching Host and Match stanzas.
152
153 CanonicalizeMaxDots
154 Specifies the maximum number of dot characters in a hostname
155 before canonicalization is disabled. The default, 1, allows a
156 single dot (i.e. hostname.subdomain).
157
158 CanonicalizePermittedCNAMEs
159 Specifies rules to determine whether CNAMEs should be followed
160 when canonicalizing hostnames. The rules consist of one or more
161 arguments of source_domain_list:target_domain_list, where
162 source_domain_list is a pattern-list of domains that may follow
163 CNAMEs in canonicalization, and target_domain_list is a pattern-
164 list of domains that they may resolve to.
165
166 For example, "*.a.example.com:*.b.example.com,*.c.example.com"
167 will allow hostnames matching "*.a.example.com" to be
168 canonicalized to names in the "*.b.example.com" or
169 "*.c.example.com" domains.
170
171 CASignatureAlgorithms
172 Specifies which algorithms are allowed for signing of
173 certificates by certificate authorities (CAs). The default is:
174
175 ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,
176 ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa
177
178 ssh(1) will not accept host certificates signed using algorithms
179 other than those specified.
180
181 CertificateFile
182 Specifies a file from which the user's certificate is read. A
183 corresponding private key must be provided separately in order to
184 use this certificate either from an IdentityFile directive or -i
185 flag to ssh(1), via ssh-agent(1), or via a PKCS11Provider or
186 SecurityKeyProvider.
187
188 Arguments to CertificateFile may use the tilde syntax to refer to
189 a user's home directory or the tokens described in the TOKENS
190 section.
191
192 It is possible to have multiple certificate files specified in
193 configuration files; these certificates will be tried in
194 sequence. Multiple CertificateFile directives will add to the
195 list of certificates used for authentication.
196
197 ChallengeResponseAuthentication
198 Specifies whether to use challenge-response authentication. The
199 argument to this keyword must be yes (the default) or no.
200
201 CheckHostIP
202 If set to yes (the default), ssh(1) will additionally check the
203 host IP address in the known_hosts file. This allows it to
204 detect if a host key changed due to DNS spoofing and will add
205 addresses of destination hosts to ~/.ssh/known_hosts in the
206 process, regardless of the setting of StrictHostKeyChecking. If
207 the option is set to no, the check will not be executed.
208
209 Ciphers
210 Specifies the ciphers allowed and their order of preference.
211 Multiple ciphers must be comma-separated. If the specified list
212 begins with a M-bM-^@M-^X+M-bM-^@M-^Y character, then the specified ciphers will be
213 appended to the default set instead of replacing them. If the
214 specified list begins with a M-bM-^@M-^X-M-bM-^@M-^Y character, then the specified
215 ciphers (including wildcards) will be removed from the default
216 set instead of replacing them. If the specified list begins with
217 a M-bM-^@M-^X^M-bM-^@M-^Y character, then the specified ciphers will be placed at the
218 head of the default set.
219
220 The supported ciphers are:
221
222 3des-cbc
223 aes128-cbc
224 aes192-cbc
225 aes256-cbc
226 aes128-ctr
227 aes192-ctr
228 aes256-ctr
229 aes128-gcm@openssh.com
230 aes256-gcm@openssh.com
231 chacha20-poly1305@openssh.com
232
233 The default is:
234
235 chacha20-poly1305@openssh.com,
236 aes128-ctr,aes192-ctr,aes256-ctr,
237 aes128-gcm@openssh.com,aes256-gcm@openssh.com
238
239 The list of available ciphers may also be obtained using "ssh -Q
240 cipher".
241
242 ClearAllForwardings
243 Specifies that all local, remote, and dynamic port forwardings
244 specified in the configuration files or on the command line be
245 cleared. This option is primarily useful when used from the
246 ssh(1) command line to clear port forwardings set in
247 configuration files, and is automatically set by scp(1) and
248 sftp(1). The argument must be yes or no (the default).
249
250 Compression
251 Specifies whether to use compression. The argument must be yes
252 or no (the default).
253
254 ConnectionAttempts
255 Specifies the number of tries (one per second) to make before
256 exiting. The argument must be an integer. This may be useful in
257 scripts if the connection sometimes fails. The default is 1.
258
259 ConnectTimeout
260 Specifies the timeout (in seconds) used when connecting to the
261 SSH server, instead of using the default system TCP timeout.
262 This timeout is applied both to establishing the connection and
263 to performing the initial SSH protocol handshake and key
264 exchange.
265
266 ControlMaster
267 Enables the sharing of multiple sessions over a single network
268 connection. When set to yes, ssh(1) will listen for connections
269 on a control socket specified using the ControlPath argument.
270 Additional sessions can connect to this socket using the same
271 ControlPath with ControlMaster set to no (the default). These
272 sessions will try to reuse the master instance's network
273 connection rather than initiating new ones, but will fall back to
274 connecting normally if the control socket does not exist, or is
275 not listening.
276
277 Setting this to ask will cause ssh(1) to listen for control
278 connections, but require confirmation using ssh-askpass(1). If
279 the ControlPath cannot be opened, ssh(1) will continue without
280 connecting to a master instance.
281
282 X11 and ssh-agent(1) forwarding is supported over these
283 multiplexed connections, however the display and agent forwarded
284 will be the one belonging to the master connection i.e. it is not
285 possible to forward multiple displays or agents.
286
287 Two additional options allow for opportunistic multiplexing: try
288 to use a master connection but fall back to creating a new one if
289 one does not already exist. These options are: auto and autoask.
290 The latter requires confirmation like the ask option.
291
292 ControlPath
293 Specify the path to the control socket used for connection
294 sharing as described in the ControlMaster section above or the
295 string none to disable connection sharing. Arguments to
296 ControlPath may use the tilde syntax to refer to a user's home
297 directory or the tokens described in the TOKENS section. It is
298 recommended that any ControlPath used for opportunistic
299 connection sharing include at least %h, %p, and %r (or
300 alternatively %C) and be placed in a directory that is not
301 writable by other users. This ensures that shared connections
302 are uniquely identified.
303
304 ControlPersist
305 When used in conjunction with ControlMaster, specifies that the
306 master connection should remain open in the background (waiting
307 for future client connections) after the initial client
308 connection has been closed. If set to no (the default), then the
309 master connection will not be placed into the background, and
310 will close as soon as the initial client connection is closed.
311 If set to yes or 0, then the master connection will remain in the
312 background indefinitely (until killed or closed via a mechanism
313 such as the "ssh -O exit"). If set to a time in seconds, or a
314 time in any of the formats documented in sshd_config(5), then the
315 backgrounded master connection will automatically terminate after
316 it has remained idle (with no client connections) for the
317 specified time.
318
319 DynamicForward
320 Specifies that a TCP port on the local machine be forwarded over
321 the secure channel, and the application protocol is then used to
322 determine where to connect to from the remote machine.
323
324 The argument must be [bind_address:]port. IPv6 addresses can be
325 specified by enclosing addresses in square brackets. By default,
326 the local port is bound in accordance with the GatewayPorts
327 setting. However, an explicit bind_address may be used to bind
328 the connection to a specific address. The bind_address of
329 localhost indicates that the listening port be bound for local
330 use only, while an empty address or M-bM-^@M-^X*M-bM-^@M-^Y indicates that the port
331 should be available from all interfaces.
332
333 Currently the SOCKS4 and SOCKS5 protocols are supported, and
334 ssh(1) will act as a SOCKS server. Multiple forwardings may be
335 specified, and additional forwardings can be given on the command
336 line. Only the superuser can forward privileged ports.
337
338 EnableSSHKeysign
339 Setting this option to yes in the global client configuration
340 file /etc/ssh/ssh_config enables the use of the helper program
341 ssh-keysign(8) during HostbasedAuthentication. The argument must
342 be yes or no (the default). This option should be placed in the
343 non-hostspecific section. See ssh-keysign(8) for more
344 information.
345
346 EscapeChar
347 Sets the escape character (default: M-bM-^@M-^X~M-bM-^@M-^Y). The escape character
348 can also be set on the command line. The argument should be a
349 single character, M-bM-^@M-^X^M-bM-^@M-^Y followed by a letter, or none to disable
350 the escape character entirely (making the connection transparent
351 for binary data).
352
353 ExitOnForwardFailure
354 Specifies whether ssh(1) should terminate the connection if it
355 cannot set up all requested dynamic, tunnel, local, and remote
356 port forwardings, (e.g. if either end is unable to bind and
357 listen on a specified port). Note that ExitOnForwardFailure does
358 not apply to connections made over port forwardings and will not,
359 for example, cause ssh(1) to exit if TCP connections to the
360 ultimate forwarding destination fail. The argument must be yes
361 or no (the default).
362
363 FingerprintHash
364 Specifies the hash algorithm used when displaying key
365 fingerprints. Valid options are: md5 and sha256 (the default).
366
367 ForwardAgent
368 Specifies whether the connection to the authentication agent (if
369 any) will be forwarded to the remote machine. The argument may
370 be yes, no (the default), an explicit path to an agent socket or
371 the name of an environment variable (beginning with M-bM-^@M-^X$M-bM-^@M-^Y) in which
372 to find the path.
373
374 Agent forwarding should be enabled with caution. Users with the
375 ability to bypass file permissions on the remote host (for the
376 agent's Unix-domain socket) can access the local agent through
377 the forwarded connection. An attacker cannot obtain key material
378 from the agent, however they can perform operations on the keys
379 that enable them to authenticate using the identities loaded into
380 the agent.
381
382 ForwardX11
383 Specifies whether X11 connections will be automatically
384 redirected over the secure channel and DISPLAY set. The argument
385 must be yes or no (the default).
386
387 X11 forwarding should be enabled with caution. Users with the
388 ability to bypass file permissions on the remote host (for the
389 user's X11 authorization database) can access the local X11
390 display through the forwarded connection. An attacker may then
391 be able to perform activities such as keystroke monitoring if the
392 ForwardX11Trusted option is also enabled.
393
394 ForwardX11Timeout
395 Specify a timeout for untrusted X11 forwarding using the format
396 described in the TIME FORMATS section of sshd_config(5). X11
397 connections received by ssh(1) after this time will be refused.
398 Setting ForwardX11Timeout to zero will disable the timeout and
399 permit X11 forwarding for the life of the connection. The
400 default is to disable untrusted X11 forwarding after twenty
401 minutes has elapsed.
402
403 ForwardX11Trusted
404 If this option is set to yes, remote X11 clients will have full
405 access to the original X11 display.
406
407 If this option is set to no (the default), remote X11 clients
408 will be considered untrusted and prevented from stealing or
409 tampering with data belonging to trusted X11 clients.
410 Furthermore, the xauth(1) token used for the session will be set
411 to expire after 20 minutes. Remote clients will be refused
412 access after this time.
413
414 See the X11 SECURITY extension specification for full details on
415 the restrictions imposed on untrusted clients.
416
417 GatewayPorts
418 Specifies whether remote hosts are allowed to connect to local
419 forwarded ports. By default, ssh(1) binds local port forwardings
420 to the loopback address. This prevents other remote hosts from
421 connecting to forwarded ports. GatewayPorts can be used to
422 specify that ssh should bind local port forwardings to the
423 wildcard address, thus allowing remote hosts to connect to
424 forwarded ports. The argument must be yes or no (the default).
425
426 GlobalKnownHostsFile
427 Specifies one or more files to use for the global host key
428 database, separated by whitespace. The default is
429 /etc/ssh/ssh_known_hosts, /etc/ssh/ssh_known_hosts2.
430
431 GSSAPIAuthentication
432 Specifies whether user authentication based on GSSAPI is allowed.
433 The default is no.
434
435 GSSAPIDelegateCredentials
436 Forward (delegate) credentials to the server. The default is no.
437
438 HashKnownHosts
439 Indicates that ssh(1) should hash host names and addresses when
440 they are added to ~/.ssh/known_hosts. These hashed names may be
441 used normally by ssh(1) and sshd(8), but they do not visually
442 reveal identifying information if the file's contents are
443 disclosed. The default is no. Note that existing names and
444 addresses in known hosts files will not be converted
445 automatically, but may be manually hashed using ssh-keygen(1).
446
447 HostbasedAuthentication
448 Specifies whether to try rhosts based authentication with public
449 key authentication. The argument must be yes or no (the
450 default).
451
452 HostbasedKeyTypes
453 Specifies the key types that will be used for hostbased
454 authentication as a comma-separated list of patterns.
455 Alternately if the specified list begins with a M-bM-^@M-^X+M-bM-^@M-^Y character,
456 then the specified key types will be appended to the default set
457 instead of replacing them. If the specified list begins with a
458 M-bM-^@M-^X-M-bM-^@M-^Y character, then the specified key types (including wildcards)
459 will be removed from the default set instead of replacing them.
460 If the specified list begins with a M-bM-^@M-^X^M-bM-^@M-^Y character, then the
461 specified key types will be placed at the head of the default
462 set. The default for this option is:
463
464 ecdsa-sha2-nistp256-cert-v01@openssh.com,
465 ecdsa-sha2-nistp384-cert-v01@openssh.com,
466 ecdsa-sha2-nistp521-cert-v01@openssh.com,
467 sk-ecdsa-sha2-nistp256-cert-v01@openssh.com,
468 ssh-ed25519-cert-v01@openssh.com,
469 sk-ssh-ed25519-cert-v01@openssh.com,
470 rsa-sha2-512-cert-v01@openssh.com,
471 rsa-sha2-256-cert-v01@openssh.com,
472 ssh-rsa-cert-v01@openssh.com,
473 ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,
474 sk-ecdsa-sha2-nistp256@openssh.com,
475 ssh-ed25519,sk-ssh-ed25519@openssh.com,
476 rsa-sha2-512,rsa-sha2-256,ssh-rsa
477
478 The -Q option of ssh(1) may be used to list supported key types.
479
480 HostKeyAlgorithms
481 Specifies the host key algorithms that the client wants to use in
482 order of preference. Alternately if the specified list begins
483 with a M-bM-^@M-^X+M-bM-^@M-^Y character, then the specified key types will be
484 appended to the default set instead of replacing them. If the
485 specified list begins with a M-bM-^@M-^X-M-bM-^@M-^Y character, then the specified
486 key types (including wildcards) will be removed from the default
487 set instead of replacing them. If the specified list begins with
488 a M-bM-^@M-^X^M-bM-^@M-^Y character, then the specified key types will be placed at
489 the head of the default set. The default for this option is:
490
491 ecdsa-sha2-nistp256-cert-v01@openssh.com,
492 ecdsa-sha2-nistp384-cert-v01@openssh.com,
493 ecdsa-sha2-nistp521-cert-v01@openssh.com,
494 sk-ecdsa-sha2-nistp256-cert-v01@openssh.com,
495 ssh-ed25519-cert-v01@openssh.com,
496 sk-ssh-ed25519-cert-v01@openssh.com,
497 rsa-sha2-512-cert-v01@openssh.com,
498 rsa-sha2-256-cert-v01@openssh.com,
499 ssh-rsa-cert-v01@openssh.com,
500 ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,
501 sk-ecdsa-sha2-nistp256@openssh.com,
502 ssh-ed25519,sk-ssh-ed25519@openssh.com,
503 rsa-sha2-512,rsa-sha2-256,ssh-rsa
504
505 If hostkeys are known for the destination host then this default
506 is modified to prefer their algorithms.
507
508 The list of available key types may also be obtained using "ssh
509 -Q HostKeyAlgorithms".
510
511 HostKeyAlias
512 Specifies an alias that should be used instead of the real host
513 name when looking up or saving the host key in the host key
514 database files and when validating host certificates. This
515 option is useful for tunneling SSH connections or for multiple
516 servers running on a single host.
517
518 Hostname
519 Specifies the real host name to log into. This can be used to
520 specify nicknames or abbreviations for hosts. Arguments to
521 Hostname accept the tokens described in the TOKENS section.
522 Numeric IP addresses are also permitted (both on the command line
523 and in Hostname specifications). The default is the name given
524 on the command line.
525
526 IdentitiesOnly
527 Specifies that ssh(1) should only use the configured
528 authentication identity and certificate files (either the default
529 files, or those explicitly configured in the ssh_config files or
530 passed on the ssh(1) command-line), even if ssh-agent(1) or a
531 PKCS11Provider or SecurityKeyProvider offers more identities.
532 The argument to this keyword must be yes or no (the default).
533 This option is intended for situations where ssh-agent offers
534 many different identities.
535
536 IdentityAgent
537 Specifies the UNIX-domain socket used to communicate with the
538 authentication agent.
539
540 This option overrides the SSH_AUTH_SOCK environment variable and
541 can be used to select a specific agent. Setting the socket name
542 to none disables the use of an authentication agent. If the
543 string "SSH_AUTH_SOCK" is specified, the location of the socket
544 will be read from the SSH_AUTH_SOCK environment variable.
545 Otherwise if the specified value begins with a M-bM-^@M-^X$M-bM-^@M-^Y character,
546 then it will be treated as an environment variable containing the
547 location of the socket.
548
549 Arguments to IdentityAgent may use the tilde syntax to refer to a
550 user's home directory or the tokens described in the TOKENS
551 section.
552
553 IdentityFile
554 Specifies a file from which the user's DSA, ECDSA, authenticator-
555 hosted ECDSA, Ed25519, authenticator-hosted Ed25519 or RSA
556 authentication identity is read. The default is ~/.ssh/id_dsa,
557 ~/.ssh/id_ecdsa, ~/.ssh/id_ecdsa_sk, ~/.ssh/id_ed25519,
558 ~/.ssh/id_ed25519_sk and ~/.ssh/id_rsa. Additionally, any
559 identities represented by the authentication agent will be used
560 for authentication unless IdentitiesOnly is set. If no
561 certificates have been explicitly specified by CertificateFile,
562 ssh(1) will try to load certificate information from the filename
563 obtained by appending -cert.pub to the path of a specified
564 IdentityFile.
565
566 Arguments to IdentityFile may use the tilde syntax to refer to a
567 user's home directory or the tokens described in the TOKENS
568 section.
569
570 It is possible to have multiple identity files specified in
571 configuration files; all these identities will be tried in
572 sequence. Multiple IdentityFile directives will add to the list
573 of identities tried (this behaviour differs from that of other
574 configuration directives).
575
576 IdentityFile may be used in conjunction with IdentitiesOnly to
577 select which identities in an agent are offered during
578 authentication. IdentityFile may also be used in conjunction
579 with CertificateFile in order to provide any certificate also
580 needed for authentication with the identity.
581
582 IgnoreUnknown
583 Specifies a pattern-list of unknown options to be ignored if they
584 are encountered in configuration parsing. This may be used to
585 suppress errors if ssh_config contains options that are
586 unrecognised by ssh(1). It is recommended that IgnoreUnknown be
587 listed early in the configuration file as it will not be applied
588 to unknown options that appear before it.
589
590 Include
591 Include the specified configuration file(s). Multiple pathnames
592 may be specified and each pathname may contain glob(7) wildcards
593 and, for user configurations, shell-like M-bM-^@M-^X~M-bM-^@M-^Y references to user
594 home directories. Files without absolute paths are assumed to be
595 in ~/.ssh if included in a user configuration file or /etc/ssh if
596 included from the system configuration file. Include directive
597 may appear inside a Match or Host block to perform conditional
598 inclusion.
599
600 IPQoS Specifies the IPv4 type-of-service or DSCP class for connections.
601 Accepted values are af11, af12, af13, af21, af22, af23, af31,
602 af32, af33, af41, af42, af43, cs0, cs1, cs2, cs3, cs4, cs5, cs6,
603 cs7, ef, le, lowdelay, throughput, reliability, a numeric value,
604 or none to use the operating system default. This option may
605 take one or two arguments, separated by whitespace. If one
606 argument is specified, it is used as the packet class
607 unconditionally. If two values are specified, the first is
608 automatically selected for interactive sessions and the second
609 for non-interactive sessions. The default is af21 (Low-Latency
610 Data) for interactive sessions and cs1 (Lower Effort) for non-
611 interactive sessions.
612
613 KbdInteractiveAuthentication
614 Specifies whether to use keyboard-interactive authentication.
615 The argument to this keyword must be yes (the default) or no.
616
617 KbdInteractiveDevices
618 Specifies the list of methods to use in keyboard-interactive
619 authentication. Multiple method names must be comma-separated.
620 The default is to use the server specified list. The methods
621 available vary depending on what the server supports. For an
622 OpenSSH server, it may be zero or more of: bsdauth and pam.
623
624 KexAlgorithms
625 Specifies the available KEX (Key Exchange) algorithms. Multiple
626 algorithms must be comma-separated. If the specified list begins
627 with a M-bM-^@M-^X+M-bM-^@M-^Y character, then the specified methods will be appended
628 to the default set instead of replacing them. If the specified
629 list begins with a M-bM-^@M-^X-M-bM-^@M-^Y character, then the specified methods
630 (including wildcards) will be removed from the default set
631 instead of replacing them. If the specified list begins with a
632 M-bM-^@M-^X^M-bM-^@M-^Y character, then the specified methods will be placed at the
633 head of the default set. The default is:
634
635 curve25519-sha256,curve25519-sha256@libssh.org,
636 ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,
637 diffie-hellman-group-exchange-sha256,
638 diffie-hellman-group16-sha512,
639 diffie-hellman-group18-sha512,
640 diffie-hellman-group14-sha256
641
642 The list of available key exchange algorithms may also be
643 obtained using "ssh -Q kex".
644
645 LocalCommand
646 Specifies a command to execute on the local machine after
647 successfully connecting to the server. The command string
648 extends to the end of the line, and is executed with the user's
649 shell. Arguments to LocalCommand accept the tokens described in
650 the TOKENS section.
651
652 The command is run synchronously and does not have access to the
653 session of the ssh(1) that spawned it. It should not be used for
654 interactive commands.
655
656 This directive is ignored unless PermitLocalCommand has been
657 enabled.
658
659 LocalForward
660 Specifies that a TCP port on the local machine be forwarded over
661 the secure channel to the specified host and port from the remote
662 machine. The first argument specifies the listener and may be
663 [bind_address:]port or a Unix domain socket path. The second
664 argument is the destination and may be host:hostport or a Unix
665 domain socket path if the remote host supports it.
666
667 IPv6 addresses can be specified by enclosing addresses in square
668 brackets. Multiple forwardings may be specified, and additional
669 forwardings can be given on the command line. Only the superuser
670 can forward privileged ports. By default, the local port is
671 bound in accordance with the GatewayPorts setting. However, an
672 explicit bind_address may be used to bind the connection to a
673 specific address. The bind_address of localhost indicates that
674 the listening port be bound for local use only, while an empty
675 address or M-bM-^@M-^X*M-bM-^@M-^Y indicates that the port should be available from
676 all interfaces. Unix domain socket paths accept the tokens
677 described in the TOKENS section.
678
679 LogLevel
680 Gives the verbosity level that is used when logging messages from
681 ssh(1). The possible values are: QUIET, FATAL, ERROR, INFO,
682 VERBOSE, DEBUG, DEBUG1, DEBUG2, and DEBUG3. The default is INFO.
683 DEBUG and DEBUG1 are equivalent. DEBUG2 and DEBUG3 each specify
684 higher levels of verbose output.
685
686 MACs Specifies the MAC (message authentication code) algorithms in
687 order of preference. The MAC algorithm is used for data
688 integrity protection. Multiple algorithms must be comma-
689 separated. If the specified list begins with a M-bM-^@M-^X+M-bM-^@M-^Y character,
690 then the specified algorithms will be appended to the default set
691 instead of replacing them. If the specified list begins with a
692 M-bM-^@M-^X-M-bM-^@M-^Y character, then the specified algorithms (including
693 wildcards) will be removed from the default set instead of
694 replacing them. If the specified list begins with a M-bM-^@M-^X^M-bM-^@M-^Y
695 character, then the specified algorithms will be placed at the
696 head of the default set.
697
698 The algorithms that contain "-etm" calculate the MAC after
699 encryption (encrypt-then-mac). These are considered safer and
700 their use recommended.
701
702 The default is:
703
704 umac-64-etm@openssh.com,umac-128-etm@openssh.com,
705 hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,
706 hmac-sha1-etm@openssh.com,
707 umac-64@openssh.com,umac-128@openssh.com,
708 hmac-sha2-256,hmac-sha2-512,hmac-sha1
709
710 The list of available MAC algorithms may also be obtained using
711 "ssh -Q mac".
712
713 NoHostAuthenticationForLocalhost
714 Disable host authentication for localhost (loopback addresses).
715 The argument to this keyword must be yes or no (the default).
716
717 NumberOfPasswordPrompts
718 Specifies the number of password prompts before giving up. The
719 argument to this keyword must be an integer. The default is 3.
720
721 PasswordAuthentication
722 Specifies whether to use password authentication. The argument
723 to this keyword must be yes (the default) or no.
724
725 PermitLocalCommand
726 Allow local command execution via the LocalCommand option or
727 using the !command escape sequence in ssh(1). The argument must
728 be yes or no (the default).
729
730 PKCS11Provider
731 Specifies which PKCS#11 provider to use or none to indicate that
732 no provider should be used (the default). The argument to this
733 keyword is a path to the PKCS#11 shared library ssh(1) should use
734 to communicate with a PKCS#11 token providing keys for user
735 authentication.
736
737 Port Specifies the port number to connect on the remote host. The
738 default is 22.
739
740 PreferredAuthentications
741 Specifies the order in which the client should try authentication
742 methods. This allows a client to prefer one method (e.g.
743 keyboard-interactive) over another method (e.g. password). The
744 default is:
745
746 gssapi-with-mic,hostbased,publickey,
747 keyboard-interactive,password
748
749 ProxyCommand
750 Specifies the command to use to connect to the server. The
751 command string extends to the end of the line, and is executed
752 using the user's shell M-bM-^@M-^XexecM-bM-^@M-^Y directive to avoid a lingering
753 shell process.
754
755 Arguments to ProxyCommand accept the tokens described in the
756 TOKENS section. The command can be basically anything, and
757 should read from its standard input and write to its standard
758 output. It should eventually connect an sshd(8) server running
759 on some machine, or execute sshd -i somewhere. Host key
760 management will be done using the Hostname of the host being
761 connected (defaulting to the name typed by the user). Setting
762 the command to none disables this option entirely. Note that
763 CheckHostIP is not available for connects with a proxy command.
764
765 This directive is useful in conjunction with nc(1) and its proxy
766 support. For example, the following directive would connect via
767 an HTTP proxy at 192.0.2.0:
768
769 ProxyCommand /usr/bin/nc -X connect -x 192.0.2.0:8080 %h %p
770
771 ProxyJump
772 Specifies one or more jump proxies as either [user@]host[:port]
773 or an ssh URI. Multiple proxies may be separated by comma
774 characters and will be visited sequentially. Setting this option
775 will cause ssh(1) to connect to the target host by first making a
776 ssh(1) connection to the specified ProxyJump host and then
777 establishing a TCP forwarding to the ultimate target from there.
778
779 Note that this option will compete with the ProxyCommand option -
780 whichever is specified first will prevent later instances of the
781 other from taking effect.
782
783 Note also that the configuration for the destination host (either
784 supplied via the command-line or the configuration file) is not
785 generally applied to jump hosts. ~/.ssh/config should be used if
786 specific configuration is required for jump hosts.
787
788 ProxyUseFdpass
789 Specifies that ProxyCommand will pass a connected file descriptor
790 back to ssh(1) instead of continuing to execute and pass data.
791 The default is no.
792
793 PubkeyAcceptedKeyTypes
794 Specifies the key types that will be used for public key
795 authentication as a comma-separated list of patterns. If the
796 specified list begins with a M-bM-^@M-^X+M-bM-^@M-^Y character, then the key types
797 after it will be appended to the default instead of replacing it.
798 If the specified list begins with a M-bM-^@M-^X-M-bM-^@M-^Y character, then the
799 specified key types (including wildcards) will be removed from
800 the default set instead of replacing them. If the specified list
801 begins with a M-bM-^@M-^X^M-bM-^@M-^Y character, then the specified key types will be
802 placed at the head of the default set. The default for this
803 option is:
804
805 ecdsa-sha2-nistp256-cert-v01@openssh.com,
806 ecdsa-sha2-nistp384-cert-v01@openssh.com,
807 ecdsa-sha2-nistp521-cert-v01@openssh.com,
808 sk-ecdsa-sha2-nistp256-cert-v01@openssh.com,
809 ssh-ed25519-cert-v01@openssh.com,
810 sk-ssh-ed25519-cert-v01@openssh.com,
811 rsa-sha2-512-cert-v01@openssh.com,
812 rsa-sha2-256-cert-v01@openssh.com,
813 ssh-rsa-cert-v01@openssh.com,
814 ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,
815 sk-ecdsa-sha2-nistp256@openssh.com,
816 ssh-ed25519,sk-ssh-ed25519@openssh.com,
817 rsa-sha2-512,rsa-sha2-256,ssh-rsa
818
819 The list of available key types may also be obtained using "ssh
820 -Q PubkeyAcceptedKeyTypes".
821
822 PubkeyAuthentication
823 Specifies whether to try public key authentication. The argument
824 to this keyword must be yes (the default) or no.
825
826 RekeyLimit
827 Specifies the maximum amount of data that may be transmitted
828 before the session key is renegotiated, optionally followed a
829 maximum amount of time that may pass before the session key is
830 renegotiated. The first argument is specified in bytes and may
831 have a suffix of M-bM-^@M-^XKM-bM-^@M-^Y, M-bM-^@M-^XMM-bM-^@M-^Y, or M-bM-^@M-^XGM-bM-^@M-^Y to indicate Kilobytes,
832 Megabytes, or Gigabytes, respectively. The default is between
833 M-bM-^@M-^X1GM-bM-^@M-^Y and M-bM-^@M-^X4GM-bM-^@M-^Y, depending on the cipher. The optional second
834 value is specified in seconds and may use any of the units
835 documented in the TIME FORMATS section of sshd_config(5). The
836 default value for RekeyLimit is default none, which means that
837 rekeying is performed after the cipher's default amount of data
838 has been sent or received and no time based rekeying is done.
839
840 RemoteCommand
841 Specifies a command to execute on the remote machine after
842 successfully connecting to the server. The command string
843 extends to the end of the line, and is executed with the user's
844 shell. Arguments to RemoteCommand accept the tokens described in
845 the TOKENS section.
846
847 RemoteForward
848 Specifies that a TCP port on the remote machine be forwarded over
849 the secure channel. The remote port may either be forwarded to a
850 specified host and port from the local machine, or may act as a
851 SOCKS 4/5 proxy that allows a remote client to connect to
852 arbitrary destinations from the local machine. The first
853 argument is the listening specification and may be
854 [bind_address:]port or, if the remote host supports it, a Unix
855 domain socket path. If forwarding to a specific destination then
856 the second argument must be host:hostport or a Unix domain socket
857 path, otherwise if no destination argument is specified then the
858 remote forwarding will be established as a SOCKS proxy.
859
860 IPv6 addresses can be specified by enclosing addresses in square
861 brackets. Multiple forwardings may be specified, and additional
862 forwardings can be given on the command line. Privileged ports
863 can be forwarded only when logging in as root on the remote
864 machine. Unix domain socket paths accept the tokens described in
865 the TOKENS section.
866
867 If the port argument is 0, the listen port will be dynamically
868 allocated on the server and reported to the client at run time.
869
870 If the bind_address is not specified, the default is to only bind
871 to loopback addresses. If the bind_address is M-bM-^@M-^X*M-bM-^@M-^Y or an empty
872 string, then the forwarding is requested to listen on all
873 interfaces. Specifying a remote bind_address will only succeed
874 if the server's GatewayPorts option is enabled (see
875 sshd_config(5)).
876
877 RequestTTY
878 Specifies whether to request a pseudo-tty for the session. The
879 argument may be one of: no (never request a TTY), yes (always
880 request a TTY when standard input is a TTY), force (always
881 request a TTY) or auto (request a TTY when opening a login
882 session). This option mirrors the -t and -T flags for ssh(1).
883
884 RevokedHostKeys
885 Specifies revoked host public keys. Keys listed in this file
886 will be refused for host authentication. Note that if this file
887 does not exist or is not readable, then host authentication will
888 be refused for all hosts. Keys may be specified as a text file,
889 listing one public key per line, or as an OpenSSH Key Revocation
890 List (KRL) as generated by ssh-keygen(1). For more information
891 on KRLs, see the KEY REVOCATION LISTS section in ssh-keygen(1).
892
893 SecurityKeyProvider
894 Specifies a path to a library that will be used when loading any
895 FIDO authenticator-hosted keys, overriding the default of using
896 the built-in USB HID support.
897
898 If the specified value begins with a M-bM-^@M-^X$M-bM-^@M-^Y character, then it will
899 be treated as an environment variable containing the path to the
900 library.
901
902 SendEnv
903 Specifies what variables from the local environ(7) should be sent
904 to the server. The server must also support it, and the server
905 must be configured to accept these environment variables. Note
906 that the TERM environment variable is always sent whenever a
907 pseudo-terminal is requested as it is required by the protocol.
908 Refer to AcceptEnv in sshd_config(5) for how to configure the
909 server. Variables are specified by name, which may contain
910 wildcard characters. Multiple environment variables may be
911 separated by whitespace or spread across multiple SendEnv
912 directives.
913
914 See PATTERNS for more information on patterns.
915
916 It is possible to clear previously set SendEnv variable names by
917 prefixing patterns with -. The default is not to send any
918 environment variables.
919
920 ServerAliveCountMax
921 Sets the number of server alive messages (see below) which may be
922 sent without ssh(1) receiving any messages back from the server.
923 If this threshold is reached while server alive messages are
924 being sent, ssh will disconnect from the server, terminating the
925 session. It is important to note that the use of server alive
926 messages is very different from TCPKeepAlive (below). The server
927 alive messages are sent through the encrypted channel and
928 therefore will not be spoofable. The TCP keepalive option
929 enabled by TCPKeepAlive is spoofable. The server alive mechanism
930 is valuable when the client or server depend on knowing when a
931 connection has become unresponsive.
932
933 The default value is 3. If, for example, ServerAliveInterval
934 (see below) is set to 15 and ServerAliveCountMax is left at the
935 default, if the server becomes unresponsive, ssh will disconnect
936 after approximately 45 seconds.
937
938 ServerAliveInterval
939 Sets a timeout interval in seconds after which if no data has
940 been received from the server, ssh(1) will send a message through
941 the encrypted channel to request a response from the server. The
942 default is 0, indicating that these messages will not be sent to
943 the server.
944
945 SetEnv Directly specify one or more environment variables and their
946 contents to be sent to the server. Similarly to SendEnv, the
947 server must be prepared to accept the environment variable.
948
949 StreamLocalBindMask
950 Sets the octal file creation mode mask (umask) used when creating
951 a Unix-domain socket file for local or remote port forwarding.
952 This option is only used for port forwarding to a Unix-domain
953 socket file.
954
955 The default value is 0177, which creates a Unix-domain socket
956 file that is readable and writable only by the owner. Note that
957 not all operating systems honor the file mode on Unix-domain
958 socket files.
959
960 StreamLocalBindUnlink
961 Specifies whether to remove an existing Unix-domain socket file
962 for local or remote port forwarding before creating a new one.
963 If the socket file already exists and StreamLocalBindUnlink is
964 not enabled, ssh will be unable to forward the port to the Unix-
965 domain socket file. This option is only used for port forwarding
966 to a Unix-domain socket file.
967
968 The argument must be yes or no (the default).
969
970 StrictHostKeyChecking
971 If this flag is set to yes, ssh(1) will never automatically add
972 host keys to the ~/.ssh/known_hosts file, and refuses to connect
973 to hosts whose host key has changed. This provides maximum
974 protection against man-in-the-middle (MITM) attacks, though it
975 can be annoying when the /etc/ssh/ssh_known_hosts file is poorly
976 maintained or when connections to new hosts are frequently made.
977 This option forces the user to manually add all new hosts.
978
979 If this flag is set to M-bM-^@M-^\accept-newM-bM-^@M-^] then ssh will automatically
980 add new host keys to the user known hosts files, but will not
981 permit connections to hosts with changed host keys. If this flag
982 is set to M-bM-^@M-^\noM-bM-^@M-^] or M-bM-^@M-^\offM-bM-^@M-^], ssh will automatically add new host keys
983 to the user known hosts files and allow connections to hosts with
984 changed hostkeys to proceed, subject to some restrictions. If
985 this flag is set to ask (the default), new host keys will be
986 added to the user known host files only after the user has
987 confirmed that is what they really want to do, and ssh will
988 refuse to connect to hosts whose host key has changed. The host
989 keys of known hosts will be verified automatically in all cases.
990
991 SyslogFacility
992 Gives the facility code that is used when logging messages from
993 ssh(1). The possible values are: DAEMON, USER, AUTH, LOCAL0,
994 LOCAL1, LOCAL2, LOCAL3, LOCAL4, LOCAL5, LOCAL6, LOCAL7. The
995 default is USER.
996
997 TCPKeepAlive
998 Specifies whether the system should send TCP keepalive messages
999 to the other side. If they are sent, death of the connection or
1000 crash of one of the machines will be properly noticed. However,
1001 this means that connections will die if the route is down
1002 temporarily, and some people find it annoying.
1003
1004 The default is yes (to send TCP keepalive messages), and the
1005 client will notice if the network goes down or the remote host
1006 dies. This is important in scripts, and many users want it too.
1007
1008 To disable TCP keepalive messages, the value should be set to no.
1009 See also ServerAliveInterval for protocol-level keepalives.
1010
1011 Tunnel Request tun(4) device forwarding between the client and the
1012 server. The argument must be yes, point-to-point (layer 3),
1013 ethernet (layer 2), or no (the default). Specifying yes requests
1014 the default tunnel mode, which is point-to-point.
1015
1016 TunnelDevice
1017 Specifies the tun(4) devices to open on the client (local_tun)
1018 and the server (remote_tun).
1019
1020 The argument must be local_tun[:remote_tun]. The devices may be
1021 specified by numerical ID or the keyword any, which uses the next
1022 available tunnel device. If remote_tun is not specified, it
1023 defaults to any. The default is any:any.
1024
1025 UpdateHostKeys
1026 Specifies whether ssh(1) should accept notifications of
1027 additional hostkeys from the server sent after authentication has
1028 completed and add them to UserKnownHostsFile. The argument must
1029 be yes, no or ask. This option allows learning alternate
1030 hostkeys for a server and supports graceful key rotation by
1031 allowing a server to send replacement public keys before old ones
1032 are removed. Additional hostkeys are only accepted if the key
1033 used to authenticate the host was already trusted or explicitly
1034 accepted by the user.
1035
1036 UpdateHostKeys is enabled by default if the user has not
1037 overridden the default UserKnownHostsFile setting, otherwise
1038 UpdateHostKeys will be set to ask.
1039
1040 If UpdateHostKeys is set to ask, then the user is asked to
1041 confirm the modifications to the known_hosts file. Confirmation
1042 is currently incompatible with ControlPersist, and will be
1043 disabled if it is enabled.
1044
1045 Presently, only sshd(8) from OpenSSH 6.8 and greater support the
1046 "hostkeys@openssh.com" protocol extension used to inform the
1047 client of all the server's hostkeys.
1048
1049 User Specifies the user to log in as. This can be useful when a
1050 different user name is used on different machines. This saves
1051 the trouble of having to remember to give the user name on the
1052 command line.
1053
1054 UserKnownHostsFile
1055 Specifies one or more files to use for the user host key
1056 database, separated by whitespace. The default is
1057 ~/.ssh/known_hosts, ~/.ssh/known_hosts2.
1058
1059 VerifyHostKeyDNS
1060 Specifies whether to verify the remote key using DNS and SSHFP
1061 resource records. If this option is set to yes, the client will
1062 implicitly trust keys that match a secure fingerprint from DNS.
1063 Insecure fingerprints will be handled as if this option was set
1064 to ask. If this option is set to ask, information on fingerprint
1065 match will be displayed, but the user will still need to confirm
1066 new host keys according to the StrictHostKeyChecking option. The
1067 default is no.
1068
1069 See also VERIFYING HOST KEYS in ssh(1).
1070
1071 VisualHostKey
1072 If this flag is set to yes, an ASCII art representation of the
1073 remote host key fingerprint is printed in addition to the
1074 fingerprint string at login and for unknown host keys. If this
1075 flag is set to no (the default), no fingerprint strings are
1076 printed at login and only the fingerprint string will be printed
1077 for unknown host keys.
1078
1079 XAuthLocation
1080 Specifies the full pathname of the xauth(1) program. The default
1081 is /usr/X11R6/bin/xauth.
1082
1083PATTERNS
1084 A pattern consists of zero or more non-whitespace characters, M-bM-^@M-^X*M-bM-^@M-^Y (a
1085 wildcard that matches zero or more characters), or M-bM-^@M-^X?M-bM-^@M-^Y (a wildcard that
1086 matches exactly one character). For example, to specify a set of
1087 declarations for any host in the ".co.uk" set of domains, the following
1088 pattern could be used:
1089
1090 Host *.co.uk
1091
1092 The following pattern would match any host in the 192.168.0.[0-9] network
1093 range:
1094
1095 Host 192.168.0.?
1096
1097 A pattern-list is a comma-separated list of patterns. Patterns within
1098 pattern-lists may be negated by preceding them with an exclamation mark
1099 (M-bM-^@M-^X!M-bM-^@M-^Y). For example, to allow a key to be used from anywhere within an
1100 organization except from the "dialup" pool, the following entry (in
1101 authorized_keys) could be used:
1102
1103 from="!*.dialup.example.com,*.example.com"
1104
1105 Note that a negated match will never produce a positive result by itself.
1106 For example, attempting to match "host3" against the following pattern-
1107 list will fail:
1108
1109 from="!host1,!host2"
1110
1111 The solution here is to include a term that will yield a positive match,
1112 such as a wildcard:
1113
1114 from="!host1,!host2,*"
1115
1116TOKENS
1117 Arguments to some keywords can make use of tokens, which are expanded at
1118 runtime:
1119
1120 %% A literal M-bM-^@M-^X%M-bM-^@M-^Y.
1121 %C Hash of %l%h%p%r.
1122 %d Local user's home directory.
1123 %h The remote hostname.
1124 %i The local user ID.
1125 %L The local hostname.
1126 %l The local hostname, including the domain name.
1127 %n The original remote hostname, as given on the command line.
1128 %p The remote port.
1129 %r The remote username.
1130 %T The local tun(4) or tap(4) network interface assigned if
1131 tunnel forwarding was requested, or "NONE" otherwise.
1132 %u The local username.
1133
1134 CertificateFile, ControlPath, IdentityAgent, IdentityFile, LocalForward,
1135 Match exec, RemoteCommand, and RemoteForward accept the tokens %%, %C,
1136 %d, %h, %i, %L, %l, %n, %p, %r, and %u.
1137
1138 Hostname accepts the tokens %% and %h.
1139
1140 LocalCommand accepts all tokens.
1141
1142 ProxyCommand accepts the tokens %%, %h, %n, %p, and %r.
1143
1144FILES
1145 ~/.ssh/config
1146 This is the per-user configuration file. The format of this file
1147 is described above. This file is used by the SSH client.
1148 Because of the potential for abuse, this file must have strict
1149 permissions: read/write for the user, and not writable by others.
1150
1151 /etc/ssh/ssh_config
1152 Systemwide configuration file. This file provides defaults for
1153 those values that are not specified in the user's configuration
1154 file, and for those users who do not have a configuration file.
1155 This file must be world-readable.
1156
1157SEE ALSO
1158 ssh(1)
1159
1160AUTHORS
1161 OpenSSH is a derivative of the original and free ssh 1.2.12 release by
1162 Tatu Ylonen. Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, Theo
1163 de Raadt and Dug Song removed many bugs, re-added newer features and
1164 created OpenSSH. Markus Friedl contributed the support for SSH protocol
1165 versions 1.5 and 2.0.
1166
1167OpenBSD 6.7 April 11, 2020 OpenBSD 6.7
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-02 11:31:36 +0000