H3C S9500 Series Operation Manual page 4

Operation Manual – VRRP
H3C S9500 Series Routing Switches
I. VRRP group
VRRP combines a group of routers on a LAN (including a master and multiple backups)
into a virtual router called VRRP group.
The VRRP group has the following features:
A virtual router has an IP address. A host on the LAN only needs to know the IP
address of the virtual router and uses the IP address as the next hop of the default
route.
Every host on the LAN communicates with external networks through the virtual
router.
Routers in the VRRP group elect the gateway according to their priorities. Once
the master acting as the gateway fails, the other routers in the VRRP group elect a
new gateway to undertake the responsibility of the failed router, thus ensuring that
the hosts in the network segment can communicate with the external networks
uninterruptedly.
Host A
Host B
Host C
Figure 1-2 Network diagram for VRRP
As shown in
has its own IP address. Hosts on the Ethernet use the virtual router as the default
gateway.
The router with the highest priority of the three routers is elected as the master to act as
the gateway, and the other two are backups.
Virtual router
Router A
Router B
Router C
Figure 1-2, Router A, Router B, and Router C form a virtual router, which
Network
1-3
Chapter 1 VRRP Configuration