H3C Technologies H3C S6800 Series Switches - Manual (Page 34)

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Creating a VRRP group and assigning a virtual IP address
A VRRP group can operate correctly after you create it and assign at least one virtual IP address to it. You
can configure multiple virtual IP addresses for the VRRP group on an interface that connects to multiple
subnets for router backup on different subnets.
Configuration guidelines
• In VRRP load balancing mode, the device supports a maximum of MaxVRNum/N VRRP groups.
MaxVRNum refers to the maximum number of VRRP groups supported by the device in VRRP
standard mode, and N refers to the number of devices in the VRRP group.
• When VRRP is operating in standard mode, the virtual IP address of a VRRP group can be either an
unused IP address on the subnet where the VRRP group resides or the IP address of an interface on
a router in the VRRP group.
• In load balancing mode, the virtual IP address of a VRRP group can be any unassigned IP address
of the subnet where the VRRP group resides, rather than the IP address of any interface in the VRRP
group. No IP address owner can exist in a VRRP group.
• When a router is the IP address owner in a VRRP group, do not configure the network command on
the interface to use the IP address of the interface, or the virtual IP address of the VRRP group, to
establish a neighbor relationship with the adjacent router. For more information about the network
command, see Layer 3—IP Routing Command Reference.
• If you create an IPv4 VRRP group but do not assign any virtual IP address for it, the VRRP group stays
in inactive state and does not function.
• Removal of the VRRP group on the IP address owner causes IP address collision. To avoid the
collision, change the IP address of the interface on the IP address owner before you remove the
VRRP group from the interface.
• The virtual IP addresses of an IPv4 VRRP group and the IP address of the downlink interface of the
VRRP group must be in the same subnet. Otherwise, the hosts in the subnet cannot access external
networks.
Configuration procedure
To create a VRRP group and assign a virtual IP address:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter interface view. interface interface-type interface-number N/A
3. Create a VRRP group
and assign a virtual IP
address.
vrrp vrid virtual-router-id virtual-ip
virtual-address
By default, no VRRP group exists.
Configuring the router priority and preemptive mode
The router priority determines which router in the VRRP group serves as the master. The preemptive mode
enables a backup to take over as the master when it detects that it has a higher priority than the current
master.