ip rip authentication

This command sets the RIP (Routing Information Protocol) Version 2 Authentication Type and Key for the specified interface or range of interfaces. The value of type is either none, simple, or encrypt. The value for authentication key [key] must be 16 bytes or less. The [key] is composed of standard displayable, noncontrol keystrokes from a Standard 101/102-key keyboard. If the value of type is encrypt, a keyid in the range of 0 and 255 must be specified. Unauthenticated interfaces do not need an authentication key or authentication key ID.