Re: X11 Forwarding

On Tue, Apr 19, 2005 at 11:42:50AM -0500, Christ, Bryan wrote:
> I have learned the hard way that sshd cannot be restarted remotely

Incorrect.

> (sshd
> does not respond to HUP).

True, but it exits cleanly on a TERM.

> Apparently, sshd forks a new sshd process
> when a new connection is made

Only a new child process.

> and the new sshd process reads the config
> file anew.  Therefore, there shouldn't be any need to restart.

Incorrect.

> Can anyone confirm this?  I've never truly found the definitive answer
> for this.

You should stop and restart the parent sshd whenever you changed the
sshd_config file.  Killing the parent sshd (the one whose PID is in
/var/run/sshd.pid) will not cause the children to be terminated, so
it's safe even over a remote ssh connection (as long as you don't lose
your session before you can start the new sshd).

I do the following all the time whenever I upgrade ssh on a remote box:

ssh remotebox
mv /usr/local/sbin/sshd /usr/local/sbin/sshd.old
put the new software in place
/sbin/init.d/ssh stop
/sbin/init.d/ssh start

My /sbin/init.d/ssh is attached for reference.  It's for HP-UX 10, but
the same principles apply to anything even remotely close to SysV init,
just with different paths.

ssh
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