Fix Slow SSH Login Time

If your login times are really high, it may be that reverse DNS is not working correctly.

Solutions:

(a) Disable DNS in SSH daemon: go to /etc/ssh/sshd_config and include the line UseDNS no, then restart ssh service: /etc/init.d/sshd restart

(b) Or, fix your DNS configuration: in redhat, go to setup -> Network Configuration -> Edit DNS configuration -> and set the primary DNS and the search domain