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linux_ssh_access [2021/04/07 14:15]
pgh5a
linux_ssh_access [2021/04/13 19:34]
pgh5a
Line 36: Line 36:
 abc1de@portal04 ~ $ hostname abc1de@portal04 ~ $ hostname
 portal04 ​                                              <​-- We are logged into portal cluster portal04 ​                                              <​-- We are logged into portal cluster
-abc1de@portal04 ~ $ ssh gpusrv01 ​                        ​<-- We can now access ​gpusrv01+abc1de@portal04 ~ $ ssh gpusrv01 ​                      ​<-- We can now '​ssh'​ to gpusrv01
 abc1de@gpusrv01'​s password: abc1de@gpusrv01'​s password:
 .... ....
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 === Jumphost Option === === Jumphost Option ===
  
-The ssh client has an option ''​%%-J%%''​ to specify a host to use as a "​jumphost"​ that lets you access other servers directly, in one step.  This combines two steps (for example, ssh into portal.cs.virginia.edu and then ssh to gpusrv01) into one single command. ​ From the //man// page: +The ssh client has an option ''​%%-J%%''​ to specify a host to use as a "​jumphost"​ that lets you access other servers directly ​with one command.  This combines two steps (for example, ssh into portal.cs.virginia.edu and then ssh to gpusrv01) into one single command.
- +
-<​code>​ +
-     -J destination +
-             ​Connect to the target host by first making a ssh connection to +
-             the jump host described by destination and then establishing a +
-             TCP forwarding to the ultimate destination from there. ​ Multiple +
-             jump hops may be specified separated by comma characters. ​ This +
-             is a shortcut to specify a ProxyJump configuration directive. +
-             Note that configuration directives supplied on the command-line +
-             ​generally apply to the destination host and not any specified +
-             jump hosts. ​ Use ~/​.ssh/​config to specify configuration for jump +
-             ​hosts. +
-</​code>​+
  
 Here is how we use this option to "​jump"​ from portal.cs to another CS server. ​ Let's repeat the example of logging in to ''​%%gpusrv01%%''​ Here is how we use this option to "​jump"​ from portal.cs to another CS server. ​ Let's repeat the example of logging in to ''​%%gpusrv01%%''​
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 <​code>​ <​code>​
 [abc1de@outside-uva ~]$ ssh abc1de@gpusrv01 -J abc1de@portal.cs.virginia.edu [abc1de@outside-uva ~]$ ssh abc1de@gpusrv01 -J abc1de@portal.cs.virginia.edu
-abc1de@portal04.cs.virginia.edu'​s password: ​                           <-- first asked to authenticate to portal +abc1de@portal04.cs.virginia.edu'​s password: ​                 <-- first asked to authenticate to portal 
-abc1de@gpusrv01'​s password: ​                                             <-- immediately able to log into gpusrv01+abc1de@gpusrv01'​s password: ​                                 <-- immediately able to log into gpusrv01
 .... ....
 abc1de@gpusrv01 ~ $ abc1de@gpusrv01 ~ $
  • linux_ssh_access.txt
  • Last modified: 2021/04/13 19:34
  • by pgh5a