3Com 10014299 manual Gateway services instead, Gateway function as the master, Multiple Standby

Troubleshooting VRRP 659

VRRP Monitoring As shown in Figure 209, even when router A is still functioning, it may want router Interface B to function as a gateway when the Internet interface connected with it does not

function properly. This can be implemented by configuring the monitoring interface.

To facilitate explanation, the standby group number is set as 1 with configuration of authorization key and timer added (which are unnecessary in this application).

1Configure router A:

[Router-Ethernet0]vrrp vrid 1 virtual-ip 202.38.160.111

[Router-Ethernet0]vrrp vrid 1 priority 120

[Router-Ethernet0]vrrp authentication-mode simple 3Com Router

[Router-Ethernet0]vrrp vrid 1 timer-advertise 5

[Router-Ethernet0]vrrp vrid 1 track serial0 reduced 30

2Configure router B:

	[Router-Ethernet0]vrrp vrid 1 virtual-ip 202.38.160.111
	[Router-Ethernet0]vrrp authentication-mode simple 3Com Router
	[Router-Ethernet0]vrrp vrid 1 timer-advertise 5
	Under normal conditions, router A functions as the gateway, but when the
	interface Serial0 of router A is malfunctioning, its priority will be reduced by 30,
	lower than that of router B so that router B will preempt to function as master for
	gateway services instead.
	When Serial0, the interface of router A, recovers, this router will resume its
	gateway function as the master.
Multiple Standby	One 3Com router is allowed to function as the standby router for many standby
Groups Configuration	groups. See Figure 209.
	Such a multi-backup configuration can implement load balancing. Some hosts
	(like host A) use hot standby group 1 as their gateways, some other hosts (like
	host B) use hot standby group 2 as their gateways. In this way, both data stream
	balancing and mutual backup are implemented.

1Configure router A:

[Router-Ethernet0]vrrp vrid 1 virtual-ip 202.38.160.111

[Router-Ethernet0]vrrp vrid 1 priority 120

[Router-Ethernet0]vrrp vrid 2 virtual-ip 202.38.160.112

2Configure router B:

[Router-Ethernet0]vrrp vrid 1 virtual-ip 202.38.160.111

[Router-Ethernet0]vrrp vrid 2 virtual-ip 202.38.160.112

[Router-Ethernet0]vrrp vrid 2 priority 120

Troubleshooting VRRP As the configuration of VRRP is not very complicated, almost all the malfunctions can be located through checking the information of configuration and debugging. Explanations are made of common failures trouble-shooting in the following part.