HSRP Standby

[John Levy]

Hello all. I'm doing a lab of HSRP and the target is when I lose reachability to the ISP I want the second router to be active.

My Topology :

I did a shutdown on fa0/0 on isp to lost reach-ability  to the ISP from R1 and check again R1 , seems to work fine but the R1 still stay active even if his Priority is now 60(as mentention in the image below - why the R3 Router don't become active?)

R1 HSRP Configuration:

interface FastEthernet0/1

ip address 192.168.1.50 255.255.255.0

duplex auto

speed auto

standby 1 ip 192.168.1.254

standby 1 priority 120

standby 1 preempt

standby 1 track 1 decrement 40

R1 Track object:

R1#show running-config | inc track

track 1 ip route 0.0.0.0 0.0.0.0 reachability

standby 1 track 1 decrement 40

R3 HSRP Configuration:

interface FastEthernet0/1

ip address 192.168.1.60 255.255.255.0

duplex auto

speed auto

standby 1 ip 192.168.1.254

!

Thanks all

[Reza Sharifi]

Hi,

Can't see the diagram you posted.

Can you post the config from both routers for the interface connecting r1 to r3?

HTH

[Meheretab Mengistu]

Hi John,

Add standby 1 preempt command on R3 router so that it could take over the Active state. When Fa0/0 of R1 is shutdown, the priority on R1 drops to 80 which is lower than priority of R3. And R3 will become Active router if standby preempt is configured on it. Otherwise, it will not.

When a higher priority router preempts a lower priority router, the router sends a Coup message. When a lower priority active router receives a Coup message or a Hello message from an active, higher priority router, the router changes to the Speak state and sends a resign message.

R3 HSRP Configuration:

interface FastEthernet0/1

ip address 192.168.1.60 255.255.255.0

duplex auto

speed auto

standby 1 ip 192.168.1.254

standby 1 preempt

HTH,

Meheretab

[John Levy]

Thanks for the response , but how is it make sense ? isn't the purpose of standby 1 preempt is if the active router with higher priority failed for some reason , the standby router will become active , but if the Router for example R1 (with the preemption) will get his link up again , he will came back to ACTIVE no matter how high the priority of R3 ? 

thank you 

[John Levy]

Thanks for the response , but how is it make sense ? isn't the purpose of standby 1 preempt is if the active router with higher priority failed for some reason , the standby router will become active , but if the Router for example R1 (with the preemption) will get his link up again , he will came back to ACTIVE no matter how high the priority of R3 ? 

thank you 

[Meheretab Mengistu]

standby 1 preempt on R1 will allow R1 to preempt when its priority is higher than R3. However, when R1's priority is lower than R3's priority and R1 is not down (meaning, R1's interface fa0/1 is UP), R3 will NOT preempt to become Active router unless standby 1 preempt is configured on it; that is how it works.

The following link demonstrates with an example:   https://www.cisco.com/c/en/us/support/docs/ip/hot-standby-router-protocol-hsrp/13780-6.html

HTH,

Meheretab

[John Levy]

I will try this 

thank you for your kindness sir