Regenerate the SSH key without disabling SSH

SR OS supports periodic rollover of the SSH symmetric key. Symmetric key rollover is important in long SSH sessions. Symmetric key rollover ensures that the encryption channel between the client and server is not jeopardized by an external hacker that is trying to break the encryption via a brute force attack.

This feature introduces symmetric key rollover on SSH client or server. The following are triggers for symmetric key rollover and negotiation:

For extra security, by default, the key re-exchange is enabled under SR OS. The default values are as follow:

        client
            bytes 1000000000
            minutes 60
            no shutdown
         exit
         server
            bytes 1000000000
            minutes 60
            no shutdown
         exit