Speedup SSH Authentication

Did you wait like 10 seconds to ssh into another machine which is just within one feet ?, Well the problem seems to be ssh authentication requires a time consuming DNS lookup.

Fix for this problem is to disable DNS lookup during authentication. Follow steps below to fix this. Open up the file /etc/ssh/sshd_config file as root user and append the following line to it.

UseDNS no

Save the file and exit the editor.Now restart ssh service by executing following command.

sudo /etc/init.d/ssh restart

From now on your ssh logins should work like a breeze.

3 comments:

Anonymous said...

Works great, thanks!

DucQuoc.wordpress.com said...

You can also specify IPv4 for SSH:
ssh -4 user@remotehost

:-)

Anonymous said...

Instead of 10 seconds I now wait 5 seconds, I guess that's better?