Vrrp Timer - H3C S5600 Series Operation Manual

Operation Manual – VRRP
H3C S5600 Series Ethernet Switches
Virtual router IP address-to-real MAC address mapping. When there is an IP
address owner in the VRRP group, a virtual router IP address may correspond to
two MAC addresses, a real MAC address of the IP address owner and a virtual
MAC address created by default. In this case, you can map virtual router IP
addresses to the real MAC address. Then hosts send packets to the IP address
owner for layer 3 forwarding according to the real MAC address.
Note:
You need to configure the mapping between the IP addresses of the VRRP group
and the MAC address before enabling VRRP feature on an S5600 Ethernet switch.
If VRRP is already enabled, the system does not support this configuration.
The number of virtual router IP addresses that can be mapped with the virtual router
MAC address is determined by the chips of the switches in the VRRP group.
A switch can belong to multiple VRRP groups. However, the number of VRRP
groups supported by a switch is determined by the chip it uses. Refer to device
specification for details.

1.1.3 VRRP Timer

There are two types of VRRP timer, the VRRP advertisement interval timer and the
VRRP preemption delay timer.
I. VRRP advertisement interval timer
The master advertises its normal operation state to the switches within the VRRP
group by sending VRRP packets once in each specified interval (determined by
the adver-interval argument).
You can adjust the interval for a master to send VRRP advertisements by setting
the VRRP advertisement interval timer. If a backup does not receive the VRRP
advertisements from the master after a period three times of the specified interval,
it considers itself as the master and sends out VRRP advertisements to reelect the
master.
II. VRRP preemption delay timer
The backup may not receive a VRRP advertisement within a period three times of
the specified interval due to excessive network traffic or network instability. In this
case, you can configure the VRRP preemption delay for backups.
If you configure the preemption delay for a backup, the switch preempts the
master if it does not receive a VRRP advertisement from the master after it waits
for a period three times of the advertisement interval and the period specified by
the preemption delay.
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Chapter 1 VRRP Configuration