The master multicasts VRRP packets periodically to declare its existence. Also, VRRP packets are used for
checking the parameters of the virtual router and electing the master.
VRRP packets are encapsulated in IP packets, with the protocol number being 112.
format of a VRRPv2 packet and
Figure 31 Format of a VRRPv2 packet
Figure 32 Format of a VRRPv3 packet
A VRRP packet comprises the following fields:
Version—Version number of the protocol, 2 for VRRPv2 and 3 for VRRPv3.
Type—Type of the VRRPv2 or VRRPv3 packet. Only one VRRP packet type is present, that is, VRRP
advertisement, which is represented by 1.
Virtual Rtr ID (VRID)—ID of the virtual router, that is, ID of the VRRP group. It ranges from 1 to 255.
Priority—Priority of the router in the VRRP group, in the range of 0 to 255. A greater value
represents a higher priority.
Virtual Rtr ID
IPv6 address 1
IPv6 address n
Authentication data 1
Authentication data 2
shows the format of a VRRPv3 packet.
Count IPv6 Addrs