H3C Technologies H3C S7500E Series Switches - Manual (Page 142)

10-9
As shown in Figure 10-6 , three VRRP groups are present:
z VRRP group 1: Router A is the master; Router B and Router C are the backups.
z VRRP group 2: Router B is the master; Router A and Router C are the backups.
z VRRP group 3: Router C is the master; Router A and Router B are the backups.
For load sharing among Router A, Router B, and Router C, hosts on the LAN need to be
configured to use VRRP group 1, 2, and 3 as the default gateways respectively. When
configuring VRRP priorities, make sure that each router holds such a priority in each VRRP
group that it will take the expected role in the group.
Configuring VRRP for IPv4
VRRP for IPv4 Configuration Task List
To form a VRRP group, perform the following configurations on each device in the VRRP group.
Complete these tasks to configure VRRP for IPv4:
Task Remarks
Specifying the Type of MAC Addresses Mapped to Virtual IP
Addresses
Optional
Creating a VRRP Group and Configuring Virtual IP Address Required
Configuring Router Priority, Preemptive Mode and Tracking Function Optional
Configuring VRRP Packet Attributes Optional
Enabling the Trap Function for VRRP Optional
Specifying the Type of MAC Addresses Mapped to Virtual IP Addresses
After you specify the type of MAC addresses mapped to the virtual IP addresses of VRRP
groups and create a VRRP group, the master in the VRRP group uses the specified type of
MAC address as the source MAC address for sending packets so that the hosts in the internal
network can learn the mapping between the IP address and the MAC address and thus forward
the packets destined to other network segments to the master.
Two types of MAC addresses are available mapped to the virtual IP address of a VRRP group:
z Virtual MAC address
By default, a virtual MAC address is automatically created for a VRRP group when the VRRP
group is created, and the virtual IP address of the VRRP group is mapped to the virtual MAC
address. When such a mapping is adopted, the hosts in the internal network do not need to
update the mapping between the IP address and MAC address when the master changes.
z Real MAC address of an interface
In case that an IP address owner exists in a VRRP group, if the virtual IP address is mapped to
the virtual MAC address, two MAC addresses are mapped to one IP address. To avoid such as
problem, map the virtual IP address of the VRRP group to the real MAC address of an interface
to forward the packets from a host to the IP address owner.