Configuring SSH to use Protocol 2 or SSHv2 in CentOS

To disable SSHv1 or SSH Protocol 1, do the following:

Check for Protocol configuration

# cat /etc/ssh/sshd_config |grep Protocol

Ensure that you should get only Protocol 2

Protocol 2

If not, Edit the /etc/ssh/sshd_config to reflect only Protocol 2

# vim /etc/ssh/sshd_config

Search for the word Protocol and make the necessary changes.

Restart OpeenSSH Server

# service sshd restart