Hello guys,

You are my last hope. I googled for hours and tried so many things but I can't find a way to fix my problem.
So there we go:

I open a SSH tunnel to my linux vps.
My client sends every 5-minutes a keepalive package and I also set the "ClientAliveInterval" value to 300 in the sshd_config.
Normally a client who connected via ssh to my vps can't timeout anymore.
BUT sometime I still have the problem that some clients get kicked.
They are still online and have internet but they get disconnected.

While searching for a solution of that problem I found the auth.log file.
There are all ssh connections logged.
Here is the line which shows when some client gets disconnected:
Jun 8 15:24:31 mainone sshd[13952]: pam_unix(sshd:session): session closed for user theuser

I searched for a way to prevent PAM to close sessions and things like that.
But I didn't find any working way.
Perhaps somebody has an idea of how to keep ssh sessions alive.

I am not that much experienced with linux and the whole system.
That's why I contact you.

I already thank you so muck for helping me.

The message doesn't mean PAM forced it to close. It just means that PAM noticed it closing. You get that for any logout.

Is there any way to see why the session got closed?
Because normally it should not get closed.

Hello there!

Could you please let us know the exact name and version of the OS i.e Linux distro?

---------- Post updated at 03:28 PM ---------- Previous update was at 03:15 PM ----------

While waiting for your answer, what's the value set for "ClientAliveCountMax"? By the way, simple math says that you need a bigger window than just exactly 300 seconds to cover the 5 minutes frequent client data.

My linux distro is "Ubuntu 11.10 x86"

ClientAliveCountMax is set to 3.
As far as I understood the ClientAliveInterval value is a number which says how much time can spent until a new keepalive paket from the server gets send.
The client sends all 300 seconds (5 minutes) a packet and the server does this too.
Or is there a failure?

Do you see any error message on the terminal itself when you get "kicked out"?

Being that TCP is packet-based, what people call being "kicked out", usually isn't. Usually, it means that one end or the other has stopped responding for whatever reason, and it's taken the TCP protocol this long to realize it.

Nothing gets shown.