
119
Figure 31
Format of a VRRPv2 packet
...
Figure 32
Format of a VRRPv3 packet
...
Version
Type
Virtual Rtr ID
Priority
Count IPv6 Addrs
Auth Type
Adver Int
Checksum
IPv6 address 1
Authentication data 1
Authentication data 2
IPv6 address n
0
7
15
23
31
3
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 0 to 255. A greater value represents
a higher priority.
•
Count IP Addrs/Count IPv6 Addrs—Number of virtual IPv4 or IPv6 addresses for the VRRP group.
A VRRP group can have multiple virtual IPv4 or IPv6 addresses.
•
Auth Type—Authentication type. 0 means no authentication, 1 means simple text authentication,
and 2 means MD5 authentication. VRRPv3 does not support MD5 authentication.
•
Adver Int—Interval for sending advertisement packets. For VRRPv2, the interval is in seconds and
defaults to 1. For VRRPv3, the interval is in centiseconds and defaults to 100.
•
Checksum—16-bit checksum for validating the data in VRRP packets.