Arch Linux

chane

Member

Registered: 2003-12-02

Posts: 93

upgraded ssh and can't start it....

I just wanted to make sure that others are sucessfully running the new sshd/ssl packages?

I just upgraded openssh (3.8p1-3) and it upgraded openssl (0.9.7d1) and pacman did not give me any errors or warnings.  I now can't start the SSHD server which is a real problem since I remotely admister the boxes 

Also, since I can't log in and the person trying to start the SSHD server at the console doesn't know that much about Linux, I don't have any more info than it failed on /etc/rc.d/sshd start.  Anyway, I figure it's a configuration mistake but now I'm travelling a bit to fix it (and will probably install telnet so that it can be manually started as a backup in the future).....

If there was something else I should look out for when upgrading to the latest versions from oppenssh 3.8p1-1, openssl 0.9.61-1, any tips are appreciated...

Thanks in advance,
Chris....

farphel

Forum Fellow

From: New Hampshire - USA

Registered: 2003-09-18

Posts: 250

Website

Re: upgraded ssh and can't start it....

I don't know why sshd won't start and I'm not aware of any problems with the upgrade, but I wanted to pass along a tip for upgrading ssh in the future.  Before doing the upgrade, fire up another sshd process and bind it to another port.  The from your client, connect to the alternate sshd and do the upgrade from that connection.  After the upgrade you can try and connect 'normally' to see if everything went smoothly (make sure to keep your alternate connection running).  That way if there is a problem, you're still connected to the old sshd on the alternate port and can fix the problem.

On the remote system, fire up another sshd and bind to another port with:

/usr/sbin/sshd -p 9992

Then on your client, connect to it with:

ssh -p 9992 remote_user@remote_host

That'll save you the trip if you run into troubles upgrading ssh in the future, since I'm sure you know that telnet is a bad bad bad bad bad bad bad bad thing.

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andy

Member

From: Germany

Registered: 2002-10-11

Posts: 374

Re: upgraded ssh and can't start it....

It's even simpler than that : Just log in several times into the remote machine. When you restart sshd it will not kill active connections ! For each connection a seperate sshd is spawned. Unless you kill that very sshd the active connections will stay up (just do a ps aux | grep sshd to check for yourself).

For normal operations, a master sshd is started which reports itself into /var/run/sshd.pid and that master sshd is restarted when you do a restart - not the child processes. Also, if sshd is started with the full path, it can restart itself upon receiving SIGHUP. No need to actually stop sshd and start again. To cite from the man page :

     sshd rereads its configuration file when it receives a hangup signal,
     SIGHUP, by executing itself with the name it was started as, i.e.,
     /usr/sbin/sshd.

I beleive, sendmail (and apache ?) behave similarly.

I have several remote machines and every time I fool with sshd I always log in a 2nd time.

chane

Member

Registered: 2003-12-02

Posts: 93

Re: upgraded ssh and can't start it....

I appreciate your help and very good things to know.  My unix/Linux knowledge is very focused (not deep) and I am learning lots every day.

Thanks again,
Chris....