I have a server running several VMs via two bridges and want to secure the host via iptables.
So I have the defaults for IN/OUTPUT: drop and FORWARD: accept, and some IN/OUTPUT rules to allow me ssh access.
Now the Problem is with this setup that ssh-sessions are seemingly freezing when a command produces some lines of output. For example
date works, but
iptables -L or
top will hang in the middle of their output.
I can kill the session with
~., login again, set iptables back to default and everything works again.
Also after setting the iptables rules it takes a while before the problem arises. I haven't been able to determine the exact timeframe, has been between 5-20 minutes i think.
Any idea what could cause such a problem or how one would go about diagnosing it?