H3C S9500E Series Configuration Manual page 111

Figure 23 Network diagram for VRRP
Host A
Host B
Host C
As shown in Figure 23, Router A, Router B, and Router C form a virtual router, which 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.
The IP address of the virtual router can be either an unused IP address on the segment where the VRRP
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group resides or the IP address of an interface on a router in the VRRP group. In the latter case, the
router is called the IP address owner.
In a VRRP group, you can configure only one IP address owner.
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Status of a router in a VRRP group includes master, backup, and initialize.
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VRRP priority
VRRP determines the role (master or backup) of each router in the VRRP group by priority. A
router with a higher priority has more opportunity to become the master.
VRRP priority is in the range of 0 to 255. The greater the number, the higher the priority. Priorities
1 to 254 are configurable. Priority 0 is reserved for special uses and priority 255 for the IP
address owner. When a router acts as the IP address owner, its running priority is always 255.
That is, the IP address owner in a VRRP group acts as the master as long as it works properly.
Working mode
A router in a VRRP group works in one of the following two modes:
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Non-preemptive mode
When a router in the VRRP group becomes the master, it stays as the master as long as it
operates normally, even if a backup is assigned a higher priority later.
Virtual router
Router A
Router B
Network
Router C
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