1976 CHAPTER 107: VRRP C ONFIGURATIONIPv6-based VRRP packet formatFigure 586 IPv6-based VRRP packet formatAs shown in Figure 586, an IPv6-based VRRP packet consists of the followingfields:■ Version: Version number of the protocol, 3 for VRRPv3.■ Type: Type of the VRRP packet. Only one VRRP packet type is present, that is,VRRP advertisement, which is represented by 1.■ Virtual Rtr ID (VRID): Number of the virtual router, that is, number of thestandby group. It ranges from 1 to 255.■ Priority: Priority of the router in the standby group, in the range 0 to 255. Agreater value represents a higher priority.■ Count IPv6 Addrs: Number of virtual IPv6 addresses for the standby group. Astandby group can have multiple virtual IPv6 addresses.■ Auth Type: Authentication type. 0 means no authentication, 1 means simpleauthentication. VRRPv3 does not support MD5 authentication.■ Adver Int: Interval for sending advertisement packets, in centiseconds. Thedefault is 100.■ Checksum: 16-bit checksum for validating the data in VRRPv3 packets.■ IPv6 Address: Virtual IPv6 address entry of the standby group. The allowednumber is given by the Count IPv6 Addrs field.■ Authentication Data: Authentication key. Currently, this field is used only forsimple authentication and is 0 for any other authentication modes.Principles of VRRP ■ With VRRP enabled, the routers determine their respective roles in the standbygroup by priority. The router with the highest priority becomes the master,...Version Type Virtual Rtr ID Priority Count IPv6 AddrsAuth Type Adver Int ChecksumIPv6 address 1Authentication data 1Authentication data 2IPv6 address n0 7 15 23 313
