VRRP
7750 SR OS Router Configuration Guide Page 179
• VRRP message checks
→Version field – Must be set to the value 2
→Type field – Must be set to the value of 1 (advertisement)
→Virtual router ID field – Must match one of the configured VRID on the ingress IP
interface (All other fields are dependent on matching the virtual router ID field to one
of the interfaces configured VRID parameters)
→Priority field – Must be equal to or greater than the VRID in-use priority or be equal to
0 (Note, equal to the VRID in-use priority and 0 requires further processing regarding
master/backup and senders IP address to determine validity of the message)
→Authentication type field – Must be equal to 0
→Advertisement interval field – Must be equal to the VRID configured advertisement
interval
→Checksum field – Must be valid
→Authentication data fields – Must be ignored.
VRRP messages not meeting the criteria are silently dropped.
Authentication Type 1 – Simple Text Password
The use of 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 place 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 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 VRID configured simple text
password
Any VRRP message not meeting the type 0 verification checks with the exceptions above are
silently discarded.