The use of authentication type 1 indicates that VRRP advertisement messages are authenticated with a clear (simple) text password. All virtual routers participating in the virtual router instance must be configured with the same 8 octet password. Transmitting virtual routers put a value of 1 in the VRRP advertisement message authentication type field and put the configured simple text password into the message authentication data field. Receiving virtual routers compare the message authentication data field with the local configured simple text password based on the message authentication type field value of 1.
The same checks are performed as for type 0, with the following exceptions (the VRRP specification may require additional checks):
VRRP message checks
Authentication type field – Must be equal to 1
Authentication data fields – Must be equal to the VRIDconfigured simple text password
Any VRRP messages not meeting the type 0 verification checks, with the preceding exceptions are silently discarded.