H3C S7500 Series Operation Manual page 583

Operation Manual – VRRP-HA
H3C S7500 Series Ethernet Switches
I. Configuring a virtual router IP address
The IP address of the virtual router can be an unassigned IP address of the network
segment where the backup group is located or the interface IP address of a member
switch in the backup group. Virtual router IP address has the following features:
You can specify the virtual router IP address as the IP address used by a member
switch in the backup group. In this case, the switch is called an IP address owner.
A backup group is established if it is assigned an IP address for the first time. If you
then add other IP addresses to the backup group, the IP addresses are added to
the virtual router IP address list of the backup group.
The virtual router IP address and the IP addresses used by the member switches
in a backup group must belong to the same network segment. If not, the backup
group will be in the initial state (the state before you configure the VRRP on the
switches of the group). In this case, VRRP does not take effect.
A backup group is removed if all its virtual router IP addresses are removed. In this
case, all the configurations performed for the backup group get ruined.
According to the standard VRRP, you will fail to use the ping command to ping the IP
address of a virtual router. So the hosts connected to a switch in a backup group cannot
judge whether an IP address is used by the backup group with ping command. If the IP
address of a host is also used by the virtual router, all packets destined for the network
segment will be forwarded to the host. In this case, data in this network segment cannot
be forwarded properly.
Before enabling VRRP feature on an S7500 switch, you can enable the switches in a
backup group to respond the ping operations destined for the virtual router IP
addresses. Therefore the above incident can be avoided. If VRRP is already enabled,
the system does not support this configuration.
II. Mapping Virtual IP Addresses to MAC Addresses
An S7500 switch provides the following functions in addition to forwarding data
correctly.
You can map multiple virtual IP addresses of the backup group to a virtual MAC
address as needed. You can also map virtual IP addresses to the MAC address of
a switch routing interface.
You need to map the IP addresses of the backup group to the MAC addresses
before enabling VRRP feature on an S7500 switch. If VRRP is already enabled,
the system does not support this configuration.
By default, virtual router IP addresses are mapped to the virtual MAC address of a
backup group.
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Chapter 1 VRRP Configuration