Changing the key-exchange method

By default, diffie-hellman-group1-sha1 is the key-exchange method used to establish an SSH connection. You can change the default key-exchange method and configure diffie-hellman-group14-sha1 as the key-exchange method using the ip ssh key-exchange-method dh-group14-sha1 command. The diffie-hellman-group14-sha1 method provides enhanced encryption of shared secrets between two devices.

NOTE
High CPU usage is expected while establishing SSH sessions with diffie-hellman-group14-sha1 key-exchange method.