1-5Packet FormatThe master multicasts VRRP packets periodically to declare its existence. VRRP packets are also usedfor checking the parameters of the virtual router and electing the master.Figure 1-3 shows the format of a VRRPv2 packet and Figure 1-4 shows the format of a VRRPv3 packet.Figure 1-3 Format of a VRRPv2 packet ...Figure 1-4 Format of a VRRPv3 packet ...Version Type Virtual Rtr ID Priority Count IPv6 AddrsAuth Type Adver Int ChecksumIPv6 address 1Authentication data 1Authentication data 2IPv6 address n0 7 15 23 313A VRRP packet consists of the following fields:z Version: Version number of the protocol, 2 for VRRPv2 and 3 for VRRPv3.z Type: Type of the VRRPv2 or VRRPv3 packet. Only one VRRP packet type is present, that is,VRRP advertisement, which is represented by 1.z Virtual Rtr ID (VRID): Serial number of the virtual router, that is, serial number of the VRRP group.It ranges from 1 to 255.z Priority: Priority of the router in the VRRP group, in the range 0 to 255. A greater value representsa higher priority.z Count IP Addrs/Count IPv6 Addrs: Number of virtual IPv4 or IPv6 addresses for the VRRP group. AVRRP group can have multiple virtual IPv4 or IPv6 addresses.
