The SSH protocol (Secure Shell) is a method for secure remote login from one device to other.SSH provides a secure channel over an unsecured network in a client-server architecture, connecting an SSH client application with an SSH server. SSH works on port 22.
It is a secure alternative to the non-protected login protocols (such as Telnet) and insecure file transfer methods (such as FTP).
Below is sample configuration to enable Secure Shell (SSHv2) version 2 on a Cisco router IOS –
Configure Hostname and DNS Domain
Generate RSA key to be used.
Enables the SSH server for local and remote authentication on the router
For SSH Version 2, the modulus size must be at least 768 bits.
Configures SSH control variables on the Router.
Configure SSH version 2 (This will disable SSH version 1)
Step 3 –
Enable SSH transport support for the virtual type terminal (vty)