Comments on: Quick SSH Tip

By: ssh tricks | The Fugue

ssh tricks | The Fugue — Sat, 14 Feb 2009 06:18:03 +0000

[...] Muhlestein posted a quick ssh tip, and then a couple of really neat gems emerged in the comments. For the sake of those who [...]

By: Yorokobi

Yorokobi — Fri, 13 Feb 2009 22:05:24 +0000

Another excellent SSH tool: ControlPath

In your .ssh/config add

Host *
ControlMaster auto
ControlPath ~/.ssh/master-%r@%h:%p
——

If you ever have to SSH to the same host simultaneously, this will save loads of time.

What it does: I SSH to machine A and do some work but I need a separate shell opened to machine A to do concurrent work so I SSH in again. With ControlPath the new session uses the current one–you log in in an instant.

Yes, GNU Screen can accomplish the same thing, but if you SSH as one user, then sudo su – , this is a great solution.

My $0.02

By: Dennis

Dennis — Fri, 13 Feb 2009 22:02:31 +0000

Both of those are great followup tips. Thanks!

By: Yorokobi

Yorokobi — Fri, 13 Feb 2009 22:00:08 +0000

OpenSSH has a tool to copy your ssh key to remote hosts: ssh-copy-id(1)

No need to cat your .pub and | it through SSH.

By: eggyknap

eggyknap — Fri, 13 Feb 2009 21:57:20 +0000

Also useful is the ForwardAgent option in your $HOME/.ssh/config. If you ssh to machine A w/ a key, and then want to go from A to machine B (which also knows about your key), you’d normally need your private key copied to machine A. But ForwardAgent, in combination with an ssh-agent on your machine, tells machine A to forward B’s authentication negotiation stuff back to your local ssh-agent. In short, you can go from A to whatever other machines you want (and from those machines to still other machines) without copying your private key all over.