1 SSH_CONFIG(5) File Formats Manual SSH_CONFIG(5)
4 ssh_config M-bM-^@M-^S OpenSSH SSH client configuration files
11 ssh(1) obtains configuration data from the following sources in the
14 1. command-line options
15 2. user's configuration file (~/.ssh/config)
16 3. system-wide configuration file (/etc/ssh/ssh_config)
18 For each parameter, the first obtained value will be used. The
19 configuration files contain sections separated by M-bM-^@M-^\HostM-bM-^@M-^] specifications,
20 and that section is only applied for hosts that match one of the patterns
21 given in the specification. The matched host name is usually the one
22 given on the command line (see the CanonicalizeHostname option for
25 Since the first obtained value for each parameter is used, more host-
26 specific declarations should be given near the beginning of the file, and
27 general defaults at the end.
29 The configuration file has the following format:
31 Empty lines and lines starting with M-bM-^@M-^X#M-bM-^@M-^Y are comments. Otherwise a line
32 is of the format M-bM-^@M-^\keyword argumentsM-bM-^@M-^]. Configuration options may be
33 separated by whitespace or optional whitespace and exactly one M-bM-^@M-^X=M-bM-^@M-^Y; the
34 latter format is useful to avoid the need to quote whitespace when
35 specifying configuration options using the ssh, scp, and sftp -o option.
36 Arguments may optionally be enclosed in double quotes (") in order to
37 represent arguments containing spaces.
39 The possible keywords and their meanings are as follows (note that
40 keywords are case-insensitive and arguments are case-sensitive):
42 Host Restricts the following declarations (up to the next Host or
43 Match keyword) to be only for those hosts that match one of the
44 patterns given after the keyword. If more than one pattern is
45 provided, they should be separated by whitespace. A single M-bM-^@M-^X*M-bM-^@M-^Y
46 as a pattern can be used to provide global defaults for all
47 hosts. The host is usually the hostname argument given on the
48 command line (see the CanonicalizeHostname option for
51 A pattern entry may be negated by prefixing it with an
52 exclamation mark (M-bM-^@M-^X!M-bM-^@M-^Y). If a negated entry is matched, then the
53 Host entry is ignored, regardless of whether any other patterns
54 on the line match. Negated matches are therefore useful to
55 provide exceptions for wildcard matches.
57 See PATTERNS for more information on patterns.
59 Match Restricts the following declarations (up to the next Host or
60 Match keyword) to be used only when the conditions following the
61 Match keyword are satisfied. Match conditions are specified
62 using one or more critera or the single token all which always
63 matches. The available criteria keywords are: canonical, exec,
64 host, originalhost, user, and localuser. The all criteria must
65 appear alone or immediately after canonical. Other criteria may
66 be combined arbitrarily. All criteria but all and canonical
67 require an argument. Criteria may be negated by prepending an
68 exclamation mark (M-bM-^@M-^X!M-bM-^@M-^Y).
70 The canonical keyword matches only when the configuration file is
71 being re-parsed after hostname canonicalization (see the
72 CanonicalizeHostname option.) This may be useful to specify
73 conditions that work with canonical host names only. The exec
74 keyword executes the specified command under the user's shell.
75 If the command returns a zero exit status then the condition is
76 considered true. Commands containing whitespace characters must
77 be quoted. The following character sequences in the command will
78 be expanded prior to execution: M-bM-^@M-^X%LM-bM-^@M-^Y will be substituted by the
79 first component of the local host name, M-bM-^@M-^X%lM-bM-^@M-^Y will be substituted
80 by the local host name (including any domain name), M-bM-^@M-^X%hM-bM-^@M-^Y will be
81 substituted by the target host name, M-bM-^@M-^X%nM-bM-^@M-^Y will be substituted by
82 the original target host name specified on the command-line, M-bM-^@M-^X%pM-bM-^@M-^Y
83 the destination port, M-bM-^@M-^X%rM-bM-^@M-^Y by the remote login username, and M-bM-^@M-^X%uM-bM-^@M-^Y
84 by the username of the user running ssh(1).
86 The other keywords' criteria must be single entries or comma-
87 separated lists and may use the wildcard and negation operators
88 described in the PATTERNS section. The criteria for the host
89 keyword are matched against the target hostname, after any
90 substitution by the Hostname or CanonicalizeHostname options.
91 The originalhost keyword matches against the hostname as it was
92 specified on the command-line. The user keyword matches against
93 the target username on the remote host. The localuser keyword
94 matches against the name of the local user running ssh(1) (this
95 keyword may be useful in system-wide ssh_config files).
98 Specifies which address family to use when connecting. Valid
99 arguments are M-bM-^@M-^\anyM-bM-^@M-^], M-bM-^@M-^\inetM-bM-^@M-^] (use IPv4 only), or M-bM-^@M-^\inet6M-bM-^@M-^] (use IPv6
103 If set to M-bM-^@M-^\yesM-bM-^@M-^], passphrase/password querying will be disabled.
104 This option is useful in scripts and other batch jobs where no
105 user is present to supply the password. The argument must be
106 M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The default is M-bM-^@M-^\noM-bM-^@M-^].
109 Use the specified address on the local machine as the source
110 address of the connection. Only useful on systems with more than
111 one address. Note that this option does not work if
112 UsePrivilegedPort is set to M-bM-^@M-^\yesM-bM-^@M-^].
115 When CanonicalizeHostname is enabled, this option specifies the
116 list of domain suffixes in which to search for the specified
119 CanonicalizeFallbackLocal
120 Specifies whether to fail with an error when hostname
121 canonicalization fails. The default, M-bM-^@M-^\yesM-bM-^@M-^], will attempt to look
122 up the unqualified hostname using the system resolver's search
123 rules. A value of M-bM-^@M-^\noM-bM-^@M-^] will cause ssh(1) to fail instantly if
124 CanonicalizeHostname is enabled and the target hostname cannot be
125 found in any of the domains specified by CanonicalDomains.
128 Controls whether explicit hostname canonicalization is performed.
129 The default, M-bM-^@M-^\noM-bM-^@M-^], is not to perform any name rewriting and let
130 the system resolver handle all hostname lookups. If set to M-bM-^@M-^\yesM-bM-^@M-^]
131 then, for connections that do not use a ProxyCommand, ssh(1) will
132 attempt to canonicalize the hostname specified on the command
133 line using the CanonicalDomains suffixes and
134 CanonicalizePermittedCNAMEs rules. If CanonicalizeHostname is
135 set to M-bM-^@M-^\alwaysM-bM-^@M-^], then canonicalization is applied to proxied
138 If this option is enabled, then the configuration files are
139 processed again using the new target name to pick up any new
140 configuration in matching Host and Match stanzas.
143 Specifies the maximum number of dot characters in a hostname
144 before canonicalization is disabled. The default, M-bM-^@M-^\1M-bM-^@M-^], allows a
145 single dot (i.e. hostname.subdomain).
147 CanonicalizePermittedCNAMEs
148 Specifies rules to determine whether CNAMEs should be followed
149 when canonicalizing hostnames. The rules consist of one or more
150 arguments of source_domain_list:target_domain_list, where
151 source_domain_list is a pattern-list of domains that may follow
152 CNAMEs in canonicalization, and target_domain_list is a pattern-
153 list of domains that they may resolve to.
155 For example, M-bM-^@M-^\*.a.example.com:*.b.example.com,*.c.example.comM-bM-^@M-^]
156 will allow hostnames matching M-bM-^@M-^\*.a.example.comM-bM-^@M-^] to be
157 canonicalized to names in the M-bM-^@M-^\*.b.example.comM-bM-^@M-^] or
158 M-bM-^@M-^\*.c.example.comM-bM-^@M-^] domains.
160 ChallengeResponseAuthentication
161 Specifies whether to use challenge-response authentication. The
162 argument to this keyword must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The default is
163 M-bM-^@M-^\yesM-bM-^@M-^].
166 If this flag is set to M-bM-^@M-^\yesM-bM-^@M-^], ssh(1) will additionally check the
167 host IP address in the known_hosts file. This allows ssh to
168 detect if a host key changed due to DNS spoofing and will add
169 addresses of destination hosts to ~/.ssh/known_hosts in the
170 process, regardless of the setting of StrictHostKeyChecking. If
171 the option is set to M-bM-^@M-^\noM-bM-^@M-^], the check will not be executed. The
172 default is M-bM-^@M-^\yesM-bM-^@M-^].
174 Cipher Specifies the cipher to use for encrypting the session in
175 protocol version 1. Currently, M-bM-^@M-^\blowfishM-bM-^@M-^], M-bM-^@M-^\3desM-bM-^@M-^], and M-bM-^@M-^\desM-bM-^@M-^] are
176 supported. des is only supported in the ssh(1) client for
177 interoperability with legacy protocol 1 implementations that do
178 not support the 3des cipher. Its use is strongly discouraged due
179 to cryptographic weaknesses. The default is M-bM-^@M-^\3desM-bM-^@M-^].
182 Specifies the ciphers allowed for protocol version 2 in order of
183 preference. Multiple ciphers must be comma-separated. If the
184 specified value begins with a M-bM-^@M-^X+M-bM-^@M-^Y character, then the specified
185 ciphers will be appended to the default set instead of replacing
188 The supported ciphers are:
197 aes128-gcm@openssh.com
198 aes256-gcm@openssh.com
204 chacha20-poly1305@openssh.com
208 chacha20-poly1305@openssh.com,
209 aes128-ctr,aes192-ctr,aes256-ctr,
210 aes128-gcm@openssh.com,aes256-gcm@openssh.com,
211 arcfour256,arcfour128,
212 aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,
213 aes192-cbc,aes256-cbc,arcfour
215 The list of available ciphers may also be obtained using the -Q
216 option of ssh(1) with an argument of M-bM-^@M-^\cipherM-bM-^@M-^].
219 Specifies that all local, remote, and dynamic port forwardings
220 specified in the configuration files or on the command line be
221 cleared. This option is primarily useful when used from the
222 ssh(1) command line to clear port forwardings set in
223 configuration files, and is automatically set by scp(1) and
224 sftp(1). The argument must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The default is
225 M-bM-^@M-^\noM-bM-^@M-^].
228 Specifies whether to use compression. The argument must be M-bM-^@M-^\yesM-bM-^@M-^]
229 or M-bM-^@M-^\noM-bM-^@M-^]. The default is M-bM-^@M-^\noM-bM-^@M-^].
232 Specifies the compression level to use if compression is enabled.
233 The argument must be an integer from 1 (fast) to 9 (slow, best).
234 The default level is 6, which is good for most applications. The
235 meaning of the values is the same as in gzip(1). Note that this
236 option applies to protocol version 1 only.
239 Specifies the number of tries (one per second) to make before
240 exiting. The argument must be an integer. This may be useful in
241 scripts if the connection sometimes fails. The default is 1.
244 Specifies the timeout (in seconds) used when connecting to the
245 SSH server, instead of using the default system TCP timeout.
246 This value is used only when the target is down or really
247 unreachable, not when it refuses the connection.
250 Enables the sharing of multiple sessions over a single network
251 connection. When set to M-bM-^@M-^\yesM-bM-^@M-^], ssh(1) will listen for
252 connections on a control socket specified using the ControlPath
253 argument. Additional sessions can connect to this socket using
254 the same ControlPath with ControlMaster set to M-bM-^@M-^\noM-bM-^@M-^] (the
255 default). These sessions will try to reuse the master instance's
256 network connection rather than initiating new ones, but will fall
257 back to connecting normally if the control socket does not exist,
260 Setting this to M-bM-^@M-^\askM-bM-^@M-^] will cause ssh to listen for control
261 connections, but require confirmation using ssh-askpass(1). If
262 the ControlPath cannot be opened, ssh will continue without
263 connecting to a master instance.
265 X11 and ssh-agent(1) forwarding is supported over these
266 multiplexed connections, however the display and agent forwarded
267 will be the one belonging to the master connection i.e. it is not
268 possible to forward multiple displays or agents.
270 Two additional options allow for opportunistic multiplexing: try
271 to use a master connection but fall back to creating a new one if
272 one does not already exist. These options are: M-bM-^@M-^\autoM-bM-^@M-^] and
273 M-bM-^@M-^\autoaskM-bM-^@M-^]. The latter requires confirmation like the M-bM-^@M-^\askM-bM-^@M-^]
277 Specify the path to the control socket used for connection
278 sharing as described in the ControlMaster section above or the
279 string M-bM-^@M-^\noneM-bM-^@M-^] to disable connection sharing. In the path, M-bM-^@M-^X%LM-bM-^@M-^Y
280 will be substituted by the first component of the local host
281 name, M-bM-^@M-^X%lM-bM-^@M-^Y will be substituted by the local host name (including
282 any domain name), M-bM-^@M-^X%hM-bM-^@M-^Y will be substituted by the target host
283 name, M-bM-^@M-^X%nM-bM-^@M-^Y will be substituted by the original target host name
284 specified on the command line, M-bM-^@M-^X%pM-bM-^@M-^Y the destination port, M-bM-^@M-^X%rM-bM-^@M-^Y by
285 the remote login username, M-bM-^@M-^X%uM-bM-^@M-^Y by the username of the user
286 running ssh(1), and M-bM-^@M-^X%CM-bM-^@M-^Y by a hash of the concatenation:
287 %l%h%p%r. It is recommended that any ControlPath used for
288 opportunistic connection sharing include at least %h, %p, and %r
289 (or alternatively %C) and be placed in a directory that is not
290 writable by other users. This ensures that shared connections
291 are uniquely identified.
294 When used in conjunction with ControlMaster, specifies that the
295 master connection should remain open in the background (waiting
296 for future client connections) after the initial client
297 connection has been closed. If set to M-bM-^@M-^\noM-bM-^@M-^], then the master
298 connection will not be placed into the background, and will close
299 as soon as the initial client connection is closed. If set to
300 M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\0M-bM-^@M-^], then the master connection will remain in the
301 background indefinitely (until killed or closed via a mechanism
302 such as the ssh(1) M-bM-^@M-^\-O exitM-bM-^@M-^] option). If set to a time in
303 seconds, or a time in any of the formats documented in
304 sshd_config(5), then the backgrounded master connection will
305 automatically terminate after it has remained idle (with no
306 client connections) for the specified time.
309 Specifies that a TCP port on the local machine be forwarded over
310 the secure channel, and the application protocol is then used to
311 determine where to connect to from the remote machine.
313 The argument must be [bind_address:]port. IPv6 addresses can be
314 specified by enclosing addresses in square brackets. By default,
315 the local port is bound in accordance with the GatewayPorts
316 setting. However, an explicit bind_address may be used to bind
317 the connection to a specific address. The bind_address of
318 M-bM-^@M-^\localhostM-bM-^@M-^] indicates that the listening port be bound for local
319 use only, while an empty address or M-bM-^@M-^X*M-bM-^@M-^Y indicates that the port
320 should be available from all interfaces.
322 Currently the SOCKS4 and SOCKS5 protocols are supported, and
323 ssh(1) will act as a SOCKS server. Multiple forwardings may be
324 specified, and additional forwardings can be given on the command
325 line. Only the superuser can forward privileged ports.
328 Setting this option to M-bM-^@M-^\yesM-bM-^@M-^] in the global client configuration
329 file /etc/ssh/ssh_config enables the use of the helper program
330 ssh-keysign(8) during HostbasedAuthentication. The argument must
331 be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The default is M-bM-^@M-^\noM-bM-^@M-^]. This option should be
332 placed in the non-hostspecific section. See ssh-keysign(8) for
336 Sets the escape character (default: M-bM-^@M-^X~M-bM-^@M-^Y). The escape character
337 can also be set on the command line. The argument should be a
338 single character, M-bM-^@M-^X^M-bM-^@M-^Y followed by a letter, or M-bM-^@M-^\noneM-bM-^@M-^] to disable
339 the escape character entirely (making the connection transparent
343 Specifies whether ssh(1) should terminate the connection if it
344 cannot set up all requested dynamic, tunnel, local, and remote
345 port forwardings. The argument must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The
346 default is M-bM-^@M-^\noM-bM-^@M-^].
349 Specifies the hash algorithm used when displaying key
350 fingerprints. Valid options are: M-bM-^@M-^\md5M-bM-^@M-^] and M-bM-^@M-^\sha256M-bM-^@M-^]. The
351 default is M-bM-^@M-^\sha256M-bM-^@M-^].
354 Specifies whether the connection to the authentication agent (if
355 any) will be forwarded to the remote machine. The argument must
356 be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The default is M-bM-^@M-^\noM-bM-^@M-^].
358 Agent forwarding should be enabled with caution. Users with the
359 ability to bypass file permissions on the remote host (for the
360 agent's Unix-domain socket) can access the local agent through
361 the forwarded connection. An attacker cannot obtain key material
362 from the agent, however they can perform operations on the keys
363 that enable them to authenticate using the identities loaded into
367 Specifies whether X11 connections will be automatically
368 redirected over the secure channel and DISPLAY set. The argument
369 must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The default is M-bM-^@M-^\noM-bM-^@M-^].
371 X11 forwarding should be enabled with caution. Users with the
372 ability to bypass file permissions on the remote host (for the
373 user's X11 authorization database) can access the local X11
374 display through the forwarded connection. An attacker may then
375 be able to perform activities such as keystroke monitoring if the
376 ForwardX11Trusted option is also enabled.
379 Specify a timeout for untrusted X11 forwarding using the format
380 described in the TIME FORMATS section of sshd_config(5). X11
381 connections received by ssh(1) after this time will be refused.
382 The default is to disable untrusted X11 forwarding after twenty
386 If this option is set to M-bM-^@M-^\yesM-bM-^@M-^], remote X11 clients will have full
387 access to the original X11 display.
389 If this option is set to M-bM-^@M-^\noM-bM-^@M-^], remote X11 clients will be
390 considered untrusted and prevented from stealing or tampering
391 with data belonging to trusted X11 clients. Furthermore, the
392 xauth(1) token used for the session will be set to expire after
393 20 minutes. Remote clients will be refused access after this
396 The default is M-bM-^@M-^\noM-bM-^@M-^].
398 See the X11 SECURITY extension specification for full details on
399 the restrictions imposed on untrusted clients.
402 Specifies whether remote hosts are allowed to connect to local
403 forwarded ports. By default, ssh(1) binds local port forwardings
404 to the loopback address. This prevents other remote hosts from
405 connecting to forwarded ports. GatewayPorts can be used to
406 specify that ssh should bind local port forwardings to the
407 wildcard address, thus allowing remote hosts to connect to
408 forwarded ports. The argument must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The
409 default is M-bM-^@M-^\noM-bM-^@M-^].
412 Specifies one or more files to use for the global host key
413 database, separated by whitespace. The default is
414 /etc/ssh/ssh_known_hosts, /etc/ssh/ssh_known_hosts2.
417 Specifies whether user authentication based on GSSAPI is allowed.
418 The default is M-bM-^@M-^\noM-bM-^@M-^]. Note that this option applies to protocol
421 GSSAPIDelegateCredentials
422 Forward (delegate) credentials to the server. The default is
423 M-bM-^@M-^\noM-bM-^@M-^]. Note that this option applies to protocol version 2 only.
426 Indicates that ssh(1) should hash host names and addresses when
427 they are added to ~/.ssh/known_hosts. These hashed names may be
428 used normally by ssh(1) and sshd(8), but they do not reveal
429 identifying information should the file's contents be disclosed.
430 The default is M-bM-^@M-^\noM-bM-^@M-^]. Note that existing names and addresses in
431 known hosts files will not be converted automatically, but may be
432 manually hashed using ssh-keygen(1).
434 HostbasedAuthentication
435 Specifies whether to try rhosts based authentication with public
436 key authentication. The argument must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The
437 default is M-bM-^@M-^\noM-bM-^@M-^]. This option applies to protocol version 2 only
438 and is similar to RhostsRSAAuthentication.
441 Specifies the key types that will be used for hostbased
442 authentication as a comma-separated pattern list. Alternately if
443 the specified value begins with a M-bM-^@M-^X+M-bM-^@M-^Y character, then the
444 specified key types will be appended to the default set instead
445 of replacing them. The default for this option is:
447 ecdsa-sha2-nistp256-cert-v01@openssh.com,
448 ecdsa-sha2-nistp384-cert-v01@openssh.com,
449 ecdsa-sha2-nistp521-cert-v01@openssh.com,
450 ssh-ed25519-cert-v01@openssh.com,
451 ssh-rsa-cert-v01@openssh.com,
452 ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,
455 The -Q option of ssh(1) may be used to list supported key types.
458 Specifies the protocol version 2 host key algorithms that the
459 client wants to use in order of preference. Alternately if the
460 specified value begins with a M-bM-^@M-^X+M-bM-^@M-^Y character, then the specified
461 key types will be appended to the default set instead of
462 replacing them. The default for this option is:
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 ssh-ed25519-cert-v01@openssh.com,
468 ssh-rsa-cert-v01@openssh.com,
469 ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,
472 If hostkeys are known for the destination host then this default
473 is modified to prefer their algorithms.
475 The list of available key types may also be obtained using the -Q
476 option of ssh(1) with an argument of M-bM-^@M-^\keyM-bM-^@M-^].
479 Specifies an alias that should be used instead of the real host
480 name when looking up or saving the host key in the host key
481 database files. This option is useful for tunneling SSH
482 connections or for multiple servers running on a single host.
485 Specifies the real host name to log into. This can be used to
486 specify nicknames or abbreviations for hosts. If the hostname
487 contains the character sequence M-bM-^@M-^X%hM-bM-^@M-^Y, then this will be replaced
488 with the host name specified on the command line (this is useful
489 for manipulating unqualified names). The character sequence M-bM-^@M-^X%%M-bM-^@M-^Y
490 will be replaced by a single M-bM-^@M-^X%M-bM-^@M-^Y character, which may be used
491 when specifying IPv6 link-local addresses.
493 The default is the name given on the command line. Numeric IP
494 addresses are also permitted (both on the command line and in
495 HostName specifications).
498 Specifies that ssh(1) should only use the authentication identity
499 files configured in the ssh_config files, even if ssh-agent(1) or
500 a PKCS11Provider offers more identities. The argument to this
501 keyword must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. This option is intended for
502 situations where ssh-agent offers many different identities. The
503 default is M-bM-^@M-^\noM-bM-^@M-^].
506 Specifies a file from which the user's DSA, ECDSA, Ed25519 or RSA
507 authentication identity is read. The default is ~/.ssh/identity
508 for protocol version 1, and ~/.ssh/id_dsa, ~/.ssh/id_ecdsa,
509 ~/.ssh/id_ed25519 and ~/.ssh/id_rsa for protocol version 2.
510 Additionally, any identities represented by the authentication
511 agent will be used for authentication unless IdentitiesOnly is
512 set. ssh(1) will try to load certificate information from the
513 filename obtained by appending -cert.pub to the path of a
514 specified IdentityFile.
516 The file name may use the tilde syntax to refer to a user's home
517 directory or one of the following escape characters: M-bM-^@M-^X%dM-bM-^@M-^Y (local
518 user's home directory), M-bM-^@M-^X%uM-bM-^@M-^Y (local user name), M-bM-^@M-^X%lM-bM-^@M-^Y (local host
519 name), M-bM-^@M-^X%hM-bM-^@M-^Y (remote host name) or M-bM-^@M-^X%rM-bM-^@M-^Y (remote user name).
521 It is possible to have multiple identity files specified in
522 configuration files; all these identities will be tried in
523 sequence. Multiple IdentityFile directives will add to the list
524 of identities tried (this behaviour differs from that of other
525 configuration directives).
527 IdentityFile may be used in conjunction with IdentitiesOnly to
528 select which identities in an agent are offered during
532 Specifies a pattern-list of unknown options to be ignored if they
533 are encountered in configuration parsing. This may be used to
534 suppress errors if ssh_config contains options that are
535 unrecognised by ssh(1). It is recommended that IgnoreUnknown be
536 listed early in the configuration file as it will not be applied
537 to unknown options that appear before it.
539 IPQoS Specifies the IPv4 type-of-service or DSCP class for connections.
540 Accepted values are M-bM-^@M-^\af11M-bM-^@M-^], M-bM-^@M-^\af12M-bM-^@M-^], M-bM-^@M-^\af13M-bM-^@M-^], M-bM-^@M-^\af21M-bM-^@M-^], M-bM-^@M-^\af22M-bM-^@M-^],
541 M-bM-^@M-^\af23M-bM-^@M-^], M-bM-^@M-^\af31M-bM-^@M-^], M-bM-^@M-^\af32M-bM-^@M-^], M-bM-^@M-^\af33M-bM-^@M-^], M-bM-^@M-^\af41M-bM-^@M-^], M-bM-^@M-^\af42M-bM-^@M-^], M-bM-^@M-^\af43M-bM-^@M-^], M-bM-^@M-^\cs0M-bM-^@M-^],
542 M-bM-^@M-^\cs1M-bM-^@M-^], M-bM-^@M-^\cs2M-bM-^@M-^], M-bM-^@M-^\cs3M-bM-^@M-^], M-bM-^@M-^\cs4M-bM-^@M-^], M-bM-^@M-^\cs5M-bM-^@M-^], M-bM-^@M-^\cs6M-bM-^@M-^], M-bM-^@M-^\cs7M-bM-^@M-^], M-bM-^@M-^\efM-bM-^@M-^],
543 M-bM-^@M-^\lowdelayM-bM-^@M-^], M-bM-^@M-^\throughputM-bM-^@M-^], M-bM-^@M-^\reliabilityM-bM-^@M-^], or a numeric value.
544 This option may take one or two arguments, separated by
545 whitespace. If one argument is specified, it is used as the
546 packet class unconditionally. If two values are specified, the
547 first is automatically selected for interactive sessions and the
548 second for non-interactive sessions. The default is M-bM-^@M-^\lowdelayM-bM-^@M-^]
549 for interactive sessions and M-bM-^@M-^\throughputM-bM-^@M-^] for non-interactive
552 KbdInteractiveAuthentication
553 Specifies whether to use keyboard-interactive authentication.
554 The argument to this keyword must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The default
555 is M-bM-^@M-^\yesM-bM-^@M-^].
557 KbdInteractiveDevices
558 Specifies the list of methods to use in keyboard-interactive
559 authentication. Multiple method names must be comma-separated.
560 The default is to use the server specified list. The methods
561 available vary depending on what the server supports. For an
562 OpenSSH server, it may be zero or more of: M-bM-^@M-^\bsdauthM-bM-^@M-^], M-bM-^@M-^\pamM-bM-^@M-^], and
563 M-bM-^@M-^\skeyM-bM-^@M-^].
566 Specifies the available KEX (Key Exchange) algorithms. Multiple
567 algorithms must be comma-separated. Alternately if the specified
568 value begins with a M-bM-^@M-^X+M-bM-^@M-^Y character, then the specified methods
569 will be appended to the default set instead of replacing them.
572 curve25519-sha256@libssh.org,
573 ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,
574 diffie-hellman-group-exchange-sha256,
575 diffie-hellman-group-exchange-sha1,
576 diffie-hellman-group14-sha1
578 The list of available key exchange algorithms may also be
579 obtained using the -Q option of ssh(1) with an argument of M-bM-^@M-^\kexM-bM-^@M-^].
582 Specifies a command to execute on the local machine after
583 successfully connecting to the server. The command string
584 extends to the end of the line, and is executed with the user's
585 shell. The following escape character substitutions will be
586 performed: M-bM-^@M-^X%dM-bM-^@M-^Y (local user's home directory), M-bM-^@M-^X%hM-bM-^@M-^Y (remote host
587 name), M-bM-^@M-^X%lM-bM-^@M-^Y (local host name), M-bM-^@M-^X%nM-bM-^@M-^Y (host name as provided on the
588 command line), M-bM-^@M-^X%pM-bM-^@M-^Y (remote port), M-bM-^@M-^X%rM-bM-^@M-^Y (remote user name) or
589 M-bM-^@M-^X%uM-bM-^@M-^Y (local user name) or M-bM-^@M-^X%CM-bM-^@M-^Y by a hash of the concatenation:
592 The command is run synchronously and does not have access to the
593 session of the ssh(1) that spawned it. It should not be used for
594 interactive commands.
596 This directive is ignored unless PermitLocalCommand has been
600 Specifies that a TCP port on the local machine be forwarded over
601 the secure channel to the specified host and port from the remote
602 machine. The first argument must be [bind_address:]port and the
603 second argument must be host:hostport. IPv6 addresses can be
604 specified by enclosing addresses in square brackets. Multiple
605 forwardings may be specified, and additional forwardings can be
606 given on the command line. Only the superuser can forward
607 privileged ports. By default, the local port is bound in
608 accordance with the GatewayPorts setting. However, an explicit
609 bind_address may be used to bind the connection to a specific
610 address. The bind_address of M-bM-^@M-^\localhostM-bM-^@M-^] indicates that the
611 listening port be bound for local use only, while an empty
612 address or M-bM-^@M-^X*M-bM-^@M-^Y indicates that the port should be available from
616 Gives the verbosity level that is used when logging messages from
617 ssh(1). The possible values are: QUIET, FATAL, ERROR, INFO,
618 VERBOSE, DEBUG, DEBUG1, DEBUG2, and DEBUG3. The default is INFO.
619 DEBUG and DEBUG1 are equivalent. DEBUG2 and DEBUG3 each specify
620 higher levels of verbose output.
622 MACs Specifies the MAC (message authentication code) algorithms in
623 order of preference. The MAC algorithm is used in protocol
624 version 2 for data integrity protection. Multiple algorithms
625 must be comma-separated. If the specified value begins with a
626 M-bM-^@M-^X+M-bM-^@M-^Y character, then the specified algorithms will be appended to
627 the default set instead of replacing them.
629 The algorithms that contain M-bM-^@M-^\-etmM-bM-^@M-^] calculate the MAC after
630 encryption (encrypt-then-mac). These are considered safer and
631 their use recommended.
635 umac-64-etm@openssh.com,umac-128-etm@openssh.com,
636 hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,
637 umac-64@openssh.com,umac-128@openssh.com,
638 hmac-sha2-256,hmac-sha2-512,
639 hmac-md5-etm@openssh.com,hmac-sha1-etm@openssh.com,
640 hmac-ripemd160-etm@openssh.com,
641 hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,
642 hmac-md5,hmac-sha1,hmac-ripemd160,
643 hmac-sha1-96,hmac-md5-96
645 The list of available MAC algorithms may also be obtained using
646 the -Q option of ssh(1) with an argument of M-bM-^@M-^\macM-bM-^@M-^].
648 NoHostAuthenticationForLocalhost
649 This option can be used if the home directory is shared across
650 machines. In this case localhost will refer to a different
651 machine on each of the machines and the user will get many
652 warnings about changed host keys. However, this option disables
653 host authentication for localhost. The argument to this keyword
654 must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The default is to check the host key for
657 NumberOfPasswordPrompts
658 Specifies the number of password prompts before giving up. The
659 argument to this keyword must be an integer. The default is 3.
661 PasswordAuthentication
662 Specifies whether to use password authentication. The argument
663 to this keyword must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The default is M-bM-^@M-^\yesM-bM-^@M-^].
666 Allow local command execution via the LocalCommand option or
667 using the !command escape sequence in ssh(1). The argument must
668 be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The default is M-bM-^@M-^\noM-bM-^@M-^].
671 Specifies which PKCS#11 provider to use. The argument to this
672 keyword is the PKCS#11 shared library ssh(1) should use to
673 communicate with a PKCS#11 token providing the user's private RSA
676 Port Specifies the port number to connect on the remote host. The
679 PreferredAuthentications
680 Specifies the order in which the client should try protocol 2
681 authentication methods. This allows a client to prefer one
682 method (e.g. keyboard-interactive) over another method (e.g.
683 password). The default is:
685 gssapi-with-mic,hostbased,publickey,
686 keyboard-interactive,password
689 Specifies the protocol versions ssh(1) should support in order of
690 preference. The possible values are M-bM-^@M-^X1M-bM-^@M-^Y and M-bM-^@M-^X2M-bM-^@M-^Y. Multiple
691 versions must be comma-separated. When this option is set to
692 M-bM-^@M-^\2,1M-bM-^@M-^] ssh will try version 2 and fall back to version 1 if
693 version 2 is not available. The default is M-bM-^@M-^X2M-bM-^@M-^Y.
696 Specifies the command to use to connect to the server. The
697 command string extends to the end of the line, and is executed
698 using the user's shell M-bM-^@M-^XexecM-bM-^@M-^Y directive to avoid a lingering
701 In the command string, any occurrence of M-bM-^@M-^X%hM-bM-^@M-^Y will be substituted
702 by the host name to connect, M-bM-^@M-^X%pM-bM-^@M-^Y by the port, and M-bM-^@M-^X%rM-bM-^@M-^Y by the
703 remote user name. The command can be basically anything, and
704 should read from its standard input and write to its standard
705 output. It should eventually connect an sshd(8) server running
706 on some machine, or execute sshd -i somewhere. Host key
707 management will be done using the HostName of the host being
708 connected (defaulting to the name typed by the user). Setting
709 the command to M-bM-^@M-^\noneM-bM-^@M-^] disables this option entirely. Note that
710 CheckHostIP is not available for connects with a proxy command.
712 This directive is useful in conjunction with nc(1) and its proxy
713 support. For example, the following directive would connect via
714 an HTTP proxy at 192.0.2.0:
716 ProxyCommand /usr/bin/nc -X connect -x 192.0.2.0:8080 %h %p
719 Specifies that ProxyCommand will pass a connected file descriptor
720 back to ssh(1) instead of continuing to execute and pass data.
721 The default is M-bM-^@M-^\noM-bM-^@M-^].
723 PubkeyAcceptedKeyTypes
724 Specifies the key types that will be used for public key
725 authentication as a comma-separated pattern list. Alternately if
726 the specified value begins with a M-bM-^@M-^X+M-bM-^@M-^Y character, then the key
727 types after it will be appended to the default instead of
728 replacing it. The default for this option is:
730 ecdsa-sha2-nistp256-cert-v01@openssh.com,
731 ecdsa-sha2-nistp384-cert-v01@openssh.com,
732 ecdsa-sha2-nistp521-cert-v01@openssh.com,
733 ssh-ed25519-cert-v01@openssh.com,
734 ssh-rsa-cert-v01@openssh.com,
735 ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,
738 The -Q option of ssh(1) may be used to list supported key types.
741 Specifies whether to try public key authentication. The argument
742 to this keyword must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The default is M-bM-^@M-^\yesM-bM-^@M-^].
743 This option applies to protocol version 2 only.
746 Specifies the maximum amount of data that may be transmitted
747 before the session key is renegotiated, optionally followed a
748 maximum amount of time that may pass before the session key is
749 renegotiated. The first argument is specified in bytes and may
750 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,
751 Megabytes, or Gigabytes, respectively. The default is between
752 M-bM-^@M-^X1GM-bM-^@M-^Y and M-bM-^@M-^X4GM-bM-^@M-^Y, depending on the cipher. The optional second
753 value is specified in seconds and may use any of the units
754 documented in the TIME FORMATS section of sshd_config(5). The
755 default value for RekeyLimit is M-bM-^@M-^\default noneM-bM-^@M-^], which means that
756 rekeying is performed after the cipher's default amount of data
757 has been sent or received and no time based rekeying is done.
758 This option applies to protocol version 2 only.
761 Specifies that a TCP port on the remote machine be forwarded over
762 the secure channel to the specified host and port from the local
763 machine. The first argument must be [bind_address:]port and the
764 second argument must be host:hostport. IPv6 addresses can be
765 specified by enclosing addresses in square brackets. Multiple
766 forwardings may be specified, and additional forwardings can be
767 given on the command line. Privileged ports can be forwarded
768 only when logging in as root on the remote machine.
770 If the port argument is M-bM-^@M-^X0M-bM-^@M-^Y, the listen port will be dynamically
771 allocated on the server and reported to the client at run time.
773 If the bind_address is not specified, the default is to only bind
774 to loopback addresses. If the bind_address is M-bM-^@M-^X*M-bM-^@M-^Y or an empty
775 string, then the forwarding is requested to listen on all
776 interfaces. Specifying a remote bind_address will only succeed
777 if the server's GatewayPorts option is enabled (see
781 Specifies whether to request a pseudo-tty for the session. The
782 argument may be one of: M-bM-^@M-^\noM-bM-^@M-^] (never request a TTY), M-bM-^@M-^\yesM-bM-^@M-^] (always
783 request a TTY when standard input is a TTY), M-bM-^@M-^\forceM-bM-^@M-^] (always
784 request a TTY) or M-bM-^@M-^\autoM-bM-^@M-^] (request a TTY when opening a login
785 session). This option mirrors the -t and -T flags for ssh(1).
788 Specifies revoked host public keys. Keys listed in this file
789 will be refused for host authentication. Note that if this file
790 does not exist or is not readable, then host authentication will
791 be refused for all hosts. Keys may be specified as a text file,
792 listing one public key per line, or as an OpenSSH Key Revocation
793 List (KRL) as generated by ssh-keygen(1). For more information
794 on KRLs, see the KEY REVOCATION LISTS section in ssh-keygen(1).
796 RhostsRSAAuthentication
797 Specifies whether to try rhosts based authentication with RSA
798 host authentication. The argument must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The
799 default is M-bM-^@M-^\noM-bM-^@M-^]. This option applies to protocol version 1 only
800 and requires ssh(1) to be setuid root.
803 Specifies whether to try RSA authentication. The argument to
804 this keyword must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. RSA authentication will only
805 be attempted if the identity file exists, or an authentication
806 agent is running. The default is M-bM-^@M-^\yesM-bM-^@M-^]. Note that this option
807 applies to protocol version 1 only.
810 Specifies what variables from the local environ(7) should be sent
811 to the server. Note that environment passing is only supported
812 for protocol 2. The server must also support it, and the server
813 must be configured to accept these environment variables. Note
814 that the TERM environment variable is always sent whenever a
815 pseudo-terminal is requested as it is required by the protocol.
816 Refer to AcceptEnv in sshd_config(5) for how to configure the
817 server. Variables are specified by name, which may contain
818 wildcard characters. Multiple environment variables may be
819 separated by whitespace or spread across multiple SendEnv
820 directives. The default is not to send any environment
823 See PATTERNS for more information on patterns.
826 Sets the number of server alive messages (see below) which may be
827 sent without ssh(1) receiving any messages back from the server.
828 If this threshold is reached while server alive messages are
829 being sent, ssh will disconnect from the server, terminating the
830 session. It is important to note that the use of server alive
831 messages is very different from TCPKeepAlive (below). The server
832 alive messages are sent through the encrypted channel and
833 therefore will not be spoofable. The TCP keepalive option
834 enabled by TCPKeepAlive is spoofable. The server alive mechanism
835 is valuable when the client or server depend on knowing when a
836 connection has become inactive.
838 The default value is 3. If, for example, ServerAliveInterval
839 (see below) is set to 15 and ServerAliveCountMax is left at the
840 default, if the server becomes unresponsive, ssh will disconnect
841 after approximately 45 seconds. This option applies to protocol
845 Sets a timeout interval in seconds after which if no data has
846 been received from the server, ssh(1) will send a message through
847 the encrypted channel to request a response from the server. The
848 default is 0, indicating that these messages will not be sent to
849 the server. This option applies to protocol version 2 only.
852 Sets the octal file creation mode mask (umask) used when creating
853 a Unix-domain socket file for local or remote port forwarding.
854 This option is only used for port forwarding to a Unix-domain
857 The default value is 0177, which creates a Unix-domain socket
858 file that is readable and writable only by the owner. Note that
859 not all operating systems honor the file mode on Unix-domain
862 StreamLocalBindUnlink
863 Specifies whether to remove an existing Unix-domain socket file
864 for local or remote port forwarding before creating a new one.
865 If the socket file already exists and StreamLocalBindUnlink is
866 not enabled, ssh will be unable to forward the port to the Unix-
867 domain socket file. This option is only used for port forwarding
868 to a Unix-domain socket file.
870 The argument must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The default is M-bM-^@M-^\noM-bM-^@M-^].
872 StrictHostKeyChecking
873 If this flag is set to M-bM-^@M-^\yesM-bM-^@M-^], ssh(1) will never automatically add
874 host keys to the ~/.ssh/known_hosts file, and refuses to connect
875 to hosts whose host key has changed. This provides maximum
876 protection against trojan horse attacks, though it can be
877 annoying when the /etc/ssh/ssh_known_hosts file is poorly
878 maintained or when connections to new hosts are frequently made.
879 This option forces the user to manually add all new hosts. If
880 this flag is set to M-bM-^@M-^\noM-bM-^@M-^], ssh will automatically add new host
881 keys to the user known hosts files. If this flag is set to
882 M-bM-^@M-^\askM-bM-^@M-^], new host keys will be added to the user known host files
883 only after the user has confirmed that is what they really want
884 to do, and ssh will refuse to connect to hosts whose host key has
885 changed. The host keys of known hosts will be verified
886 automatically in all cases. The argument must be M-bM-^@M-^\yesM-bM-^@M-^], M-bM-^@M-^\noM-bM-^@M-^], or
887 M-bM-^@M-^\askM-bM-^@M-^]. The default is M-bM-^@M-^\askM-bM-^@M-^].
890 Specifies whether the system should send TCP keepalive messages
891 to the other side. If they are sent, death of the connection or
892 crash of one of the machines will be properly noticed. However,
893 this means that connections will die if the route is down
894 temporarily, and some people find it annoying.
896 The default is M-bM-^@M-^\yesM-bM-^@M-^] (to send TCP keepalive messages), and the
897 client will notice if the network goes down or the remote host
898 dies. This is important in scripts, and many users want it too.
900 To disable TCP keepalive messages, the value should be set to
901 M-bM-^@M-^\noM-bM-^@M-^].
903 Tunnel Request tun(4) device forwarding between the client and the
904 server. The argument must be M-bM-^@M-^\yesM-bM-^@M-^], M-bM-^@M-^\point-to-pointM-bM-^@M-^] (layer 3),
905 M-bM-^@M-^\ethernetM-bM-^@M-^] (layer 2), or M-bM-^@M-^\noM-bM-^@M-^]. Specifying M-bM-^@M-^\yesM-bM-^@M-^] requests the
906 default tunnel mode, which is M-bM-^@M-^\point-to-pointM-bM-^@M-^]. The default is
907 M-bM-^@M-^\noM-bM-^@M-^].
910 Specifies the tun(4) devices to open on the client (local_tun)
911 and the server (remote_tun).
913 The argument must be local_tun[:remote_tun]. The devices may be
914 specified by numerical ID or the keyword M-bM-^@M-^\anyM-bM-^@M-^], which uses the
915 next available tunnel device. If remote_tun is not specified, it
916 defaults to M-bM-^@M-^\anyM-bM-^@M-^]. The default is M-bM-^@M-^\any:anyM-bM-^@M-^].
919 Specifies whether ssh(1) should accept notifications of
920 additional hostkeys from the server sent after authentication has
921 completed and add them to UserKnownHostsFile. The argument must
922 be M-bM-^@M-^\yesM-bM-^@M-^], M-bM-^@M-^\noM-bM-^@M-^] (the default) or M-bM-^@M-^\askM-bM-^@M-^]. Enabling this option
923 allows learning alternate hostkeys for a server and supports
924 graceful key rotation by allowing a server to send replacement
925 public keys before old ones are removed. Additional hostkeys are
926 only accepted if the key used to authenticate the host was
927 already trusted or explicity accepted by the user. If
928 UpdateHostKeys is set to M-bM-^@M-^\askM-bM-^@M-^], then the user is asked to confirm
929 the modifications to the known_hosts file. Confirmation is
930 currently incompatible with ControlPersist, and will be disabled
933 Presently, only sshd(8) from OpenSSH 6.8 and greater support the
934 M-bM-^@M-^\hostkeys@openssh.comM-bM-^@M-^] protocol extension used to inform the
935 client of all the server's hostkeys.
938 Specifies whether to use a privileged port for outgoing
939 connections. The argument must be M-bM-^@M-^\yesM-bM-^@M-^] or M-bM-^@M-^\noM-bM-^@M-^]. The default is
940 M-bM-^@M-^\noM-bM-^@M-^]. If set to M-bM-^@M-^\yesM-bM-^@M-^], ssh(1) must be setuid root. Note that
941 this option must be set to M-bM-^@M-^\yesM-bM-^@M-^] for RhostsRSAAuthentication with
944 User Specifies the user to log in as. This can be useful when a
945 different user name is used on different machines. This saves
946 the trouble of having to remember to give the user name on the
950 Specifies one or more files to use for the user host key
951 database, separated by whitespace. The default is
952 ~/.ssh/known_hosts, ~/.ssh/known_hosts2.
955 Specifies whether to verify the remote key using DNS and SSHFP
956 resource records. If this option is set to M-bM-^@M-^\yesM-bM-^@M-^], the client
957 will implicitly trust keys that match a secure fingerprint from
958 DNS. Insecure fingerprints will be handled as if this option was
959 set to M-bM-^@M-^\askM-bM-^@M-^]. If this option is set to M-bM-^@M-^\askM-bM-^@M-^], information on
960 fingerprint match will be displayed, but the user will still need
961 to confirm new host keys according to the StrictHostKeyChecking
962 option. The argument must be M-bM-^@M-^\yesM-bM-^@M-^], M-bM-^@M-^\noM-bM-^@M-^], or M-bM-^@M-^\askM-bM-^@M-^]. The default
963 is M-bM-^@M-^\noM-bM-^@M-^]. Note that this option applies to protocol version 2
966 See also VERIFYING HOST KEYS in ssh(1).
969 If this flag is set to M-bM-^@M-^\yesM-bM-^@M-^], an ASCII art representation of the
970 remote host key fingerprint is printed in addition to the
971 fingerprint string at login and for unknown host keys. If this
972 flag is set to M-bM-^@M-^\noM-bM-^@M-^], no fingerprint strings are printed at login
973 and only the fingerprint string will be printed for unknown host
974 keys. The default is M-bM-^@M-^\noM-bM-^@M-^].
977 Specifies the full pathname of the xauth(1) program. The default
978 is /usr/X11R6/bin/xauth.
981 A pattern consists of zero or more non-whitespace characters, M-bM-^@M-^X*M-bM-^@M-^Y (a
982 wildcard that matches zero or more characters), or M-bM-^@M-^X?M-bM-^@M-^Y (a wildcard that
983 matches exactly one character). For example, to specify a set of
984 declarations for any host in the M-bM-^@M-^\.co.ukM-bM-^@M-^] set of domains, the following
985 pattern could be used:
989 The following pattern would match any host in the 192.168.0.[0-9] network
994 A pattern-list is a comma-separated list of patterns. Patterns within
995 pattern-lists may be negated by preceding them with an exclamation mark
996 (M-bM-^@M-^X!M-bM-^@M-^Y). For example, to allow a key to be used from anywhere within an
997 organization except from the M-bM-^@M-^\dialupM-bM-^@M-^] pool, the following entry (in
998 authorized_keys) could be used:
1000 from="!*.dialup.example.com,*.example.com"
1004 This is the per-user configuration file. The format of this file
1005 is described above. This file is used by the SSH client.
1006 Because of the potential for abuse, this file must have strict
1007 permissions: read/write for the user, and not accessible by
1011 Systemwide configuration file. This file provides defaults for
1012 those values that are not specified in the user's configuration
1013 file, and for those users who do not have a configuration file.
1014 This file must be world-readable.
1020 OpenSSH is a derivative of the original and free ssh 1.2.12 release by
1021 Tatu Ylonen. Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, Theo
1022 de Raadt and Dug Song removed many bugs, re-added newer features and
1023 created OpenSSH. Markus Friedl contributed the support for SSH protocol
1024 versions 1.5 and 2.0.
1026 OpenBSD 5.8 August 14, 2015 OpenBSD 5.8
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