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New Member

HSRP preempt problem

Hi,

I need some advice about preempting. What I want is when Router_1 goes down Router_2 takes his place and stay that way. Even if Router_1 comes back. This is to mantain the network as stable as possible.

This is my config:

!------------ Router_1 --------------------

interface FastEthernet0/0

ip address 192.168.0.2 255.255.255.0

standby ip 192.168.0.1

standby priority 110

!------------ Router_2 ---------------------

interface FastEthernet0/0

ip address 192.168.0.3 255.255.255.0

standby ip 192.168.0.1

standby priority 90

I don't use standby preempt to avoid Router_1 coming back any minute and causing a new HSRP election, I do want Router_1 active (that's why it has higher priority), but maybe later in a more controlled enviroment like a scheduled maintenance window.

However I'm having some issues. End users cannot ping the virtual IP when Router_2 is active. I'm not sure if this is related to ARP or something else like IP Redirects.

Am I missing something on my config? a virtual MAC address would help?

standby preempt delay reload

Might work but do I really need a reload?

Any help is greatly appreciated.

Carlos

4 REPLIES
New Member

Re: HSRP preempt problem

I forgot to mention.

I'm using IOS 12.3(3a) and both routers are 3745's.

New Member

Re: HSRP preempt problem

1.First thing you need to check is if both the routers are able to ping each other using their real IP.

2.check if both the routers LAN interface real IP's are reachable from the PCs.

3.Both the routes should be able to ping to the virtual IP.

3.When first router fails, does PC's are able reach second router realIP.?

4.can you past " Show standby " of both the routers.

New Member

Re: HSRP preempt problem

You won't need preempt if you want Router_2 to remain active if Router_1 goes down and comes back up. Just leave it out. Router_1 will come back if and only if Router_2 goes down.

The virtual mac should be the same on both routers. This is to allow redundancy. Otherwise, the newly active router would need to send a gratuitous ARP everytime the other router fails. You may want to check at the client side what their local ARP entry is for the virtual IP and, verify on the routers that the newly active router is actually the active for the group - show standby. A sniffer trace will always help as well.

New Member

Re: HSRP preempt problem

You won't need preempt if you want Router_2 to remain active if Router_1 goes down and comes back up. Just leave it out. Router_1 will come back if and only if Router_2 goes down.

The virtual mac should be the same on both routers. This is to allow redundancy. Otherwise, the newly active router would need to send a gratuitous ARP everytime the other router fails. You may want to check at the client side what their local ARP entry is for the virtual IP and, verify on the routers that the newly active router is actually the active for the group - show standby. A sniffer trace will always help as well.

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