ssh login takes much time

If the ssh login to a machine needs much time (more than 10 seconds) then put the line
UseDNS no to the sshd_config on the machine you want to connect to and restart the daemon.

If it is still slow then check if the /etc/hosts file contains the proc that you were about to connect from.
The point is that you do not only need to resolve the name of the proc that you want to connect to but also the name of the proc you connect from.

This really works and the login time should be below one second.