Fixing slow SSH logins

I've noticed recently that logging in to my server over SSH has a delay of 5 to 10 seconds, which gets irritating. The problem has to do with SSHD trying to resolve IP addresses of incoming connections. Add "UseDNS no" to sshd's config file and it all goes away.

# echo "UseDNS no" >> /etc/ssh/sshd_config

Restart your DNS server and it should log in instantly.