I've had Nomachine NX server, node, and client 3.5 set up on my Ubuntu 12.04 LTS machine for a quite a while now and it has always worked fine.
Recently I tried to remote log in (from outside the subnet) and I've found that it no longer works.
I've narrowed down the problem to the SSHD daemon. The port is set to a non default one, 8888.
If I do:
ssh -v localhost
from the command line (non-root), it works fine and I see the appropriate [SSHD] messages in the auth.log file.
However, when I try to SSH log in from another machine, even within the same subnet, SSHD doesn't kick in at all and accept in the incoming request. The putty client just "sits there" and says nothing for like 15 minutes and so I have to close it.
However, the SSHD daemon does seem to be listening correctly:
paul@Paul-BluePC:/var/log$ ps -A | grep sshd
3169 ? 00:00:00 sshd
paul@Paul-BluePC:/var/log$ sudo ss -lnp | grep sshd
LISTEN 0 128 :::8888 :::* users("sshd",3169,4))
LISTEN 0 128 *:8888 *:* users("sshd",3169,3))
Moreover, my sshd_config and hosts.allow files are set correctly (they are identical to other working configurations I have on other NX server machines).
I am not seeing any [SSHD] messages come up in the auth.log, so it makes me think SSHD isn't responding, but maybe it's not even getting the requests?