H3C Technologies H3C SecBlade LB Cards - Manual (Page 19)

11
In an IPv4 network, a load-balanced VRRP group works as follows:
1. The master assigns virtual MAC addresses to all members, including itself. This example assumes
that the virtual IP address of the VRRP group is 10.1.1.1/24, Router A is the master, and Router B
is the backup. Router A assigns 000f-e2ff-0011 to itself and 000f-e2ff-0012 to Router B.
Figure 7 Virtual MAC address assignment
2. When an ARP request arrives, the master (Router A) selects a virtual MAC address based on the
load balancing algorithm to answer the ARP request. In this example, Router A returns the virtual
MAC address of itself in response to the ARP request from Host A. It returns the virtual MAC
address of Router B in response to the ARP request from Host B (see Figure 8 ).
Figure 8 Answering ARP requests
3. Each host sends packets to the returned MAC address. As shown in Figure 9 , Host A sends packets
to Router A and Host B sends packets to Router B.
Host A Host B
Router A
Master
Router B
Backup
Virtual IP: 10.1.1.1/24
Network
Gateway IP: 10.1.1.1/24 Gateway IP: 10.1.1.1/24
Virtual MAC: 000f-e2ff-0011
Virtual MAC: 000f-e2ff-0012
ARP request
Target IP: 10.1.1.1/24
ARP reply
Target MAC: 000f-e2ff-0011
ARP request
Target IP: 10.1.1.1/24
ARP reply
Target MAC: 000f-e2ff-0012