how to check whether the ssh tunnel is up

[Vincent Lin]

Hi Daniel,

Is it the only way to check the tunnel on the remote server side? How about
on the local client side?

Thanks,
Vincent


On Sat, Apr 27, 2013 at 2:22 PM, Daniel Kahn Gillmor
<dkg at fifthhorseman.net>wrote:

> On 04/26/2013 05:06 PM, Vincent Lin wrote:
>
> > I use the command below to set up a ssh tunnel. And I run it as a daemon
> > process to keep the ssh tunnel work all the time. And I should wait for
> the
> > ssh tunnel to be up and notify the tunnel is OK before sending any
> command
> > to the remote port on the remote server. But the question is I don't know
> > how to check the ssh tunnel status. Is there a way to show whether the
> ssh
> > tunnel is up?  Thank you for your help.
>
> I recommend using -oExitOnForwardFailure=yes in such a configuration.
>
> You could also look into the various keepalive options (TCPKeepAlive,
> ServerAliveCountMax, ServerAliveInterval) to ensure that your process
> terminates when the connection is no longer established.
>
> This reduces your problem to ensuring that your daemon process is still
> running (and there are a number of good solutions for that sort of
> daemon supervision -- e.g. runit, daemontools, systemd, etc)
>
> Finally, you could test whether the tunnel is up by sending traffic over
> it and seeing if there is a response :)
>
> hth,
>
>         --dkg
>
>