I too am seeing 25 second delays when I log in by ssh. I can turn
the problem on and off exactly as described in #86:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=770135#86
When the problem is "on", many things are broken in addition to slow ssh
login. The "shutdown" and "reboot" commands do nothing. Starting and
stopping services fails with a timeout. The latter in turn often breaks
"apt-get upgrade".
Sometimes the problem turns "on" when the server has been up for a long
time. I don't know what event triggers it.
Alistair
