I'm new to VRRP and I have a question that may sound stupid, but I couldn't find the answer in the Internet
If we consider the topolgy attached. We want to transfer info between R1 and R4 using R2 and R3. R1 has default-gateway: 192.168.1.3 and R4 : 10.0.0.3. We consider VRRP on R2 and R3, such as R3 is the master, and R2 - Backup (on both interfaces)
Ok. If R3 fails - R2 will take over. But, if only one interface from R3 fails (for example F0/0). Then - R1 starts transmitting to F0/0 of R2, which forwards the info to R4. But, when R4 replies - he will still send the data to R3's F1/0 interface, as he sees it as Master. R3 will have to drop the data, since it's F0/0 is down.
If we shut down both interfaces of R3 - then R2 completely takes over and the transmission goes well. How can this problem be solved ?
This problem can be solved by tracking the interfaces & decrementing the priority of the HSRP interface if other interfaces are down.
If R3 is the master, then I assume it has higher priority, let's say 110.
R2 has 100, so it's backup.
If we configure tracking on R3 so that in case Fa0/0 goes does, it decrements the priority by 15 & makes it 95. This would call for a failover & R2 will become master.
Router3(config)# track 1 interface fa0/1 line-protocol
Router3(config)# interface fa0/0
Router3(config-if)# ip address 192.168.1.x 255.0.0.0
Router3(config-if)# vrrp 1 ip 192.168.1.3
Router3(config-if)# vrrp 1 priority 110
Router3(config-if)# vrrp 1 track 1 decrement 15
Router3(config-if)# vrrp 1 preempt
Same goes for Fa0/1
Take a look at the foll doc:
However - I still have one question: in this case - would it be correct to make the 2 interfaces of every router - members of the same VRRP Group ? or different groups ?.
For example: R2: F0/0 - VRRP 1 ; F1/0 - VRRP 2
R3: F0/0 - VRRP 1 ; F1/0 - VRRP 2
R2: F0/0 - VRRP 1 ; F1/0 - VRRP 1
R3: F0/0 - VRRP 1 ; F1/0 - VRRP 1
configuring tracking is only for interfaces not participating in the vrrp group.
Configuring multiple groups is often used for load sharing: