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GLBP configuration

Unanswered Question
Jul 26th, 2006
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I have recently configured GLBP on my internet routers. It seems to work, but only for a short time. I have two Checkpoint routers in failover mode connected to a switch which is in turn connected to both of my Internet firewalls. Outbound traffic will load balance for a few hours, then switch to one of the two routers. Both routers are running 12.4(3E) IPBASEK9-M software. I have included the config statements for both routers (on the interfaces connected to our network) and the 'sho glpb' command from each router. Can anyone help?

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globalnettech Wed, 07/26/2006 - 12:33
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can you run the following debug commands and post the output:

debug glbp errors

debug condition glbp

debug glbp events



jfarrer Mon, 08/07/2006 - 08:03
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I was wondering if anyone has had a chance to review the debugs



rafaelgarcia Mon, 08/07/2006 - 10:02
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I am not quite sure about your setup but I am going to assume you are using both routers at the same time to load balance traffic out to the internet.

I have configured GLBP in a lab enviroment ans so far so good.

What I have done differently:

1. You might want to change the priority on one of the routers.Both of your routers have the same priority.

2. I can't find where you have configured the threshold decrement. This is the one that makes your router (the one with issues at the moment) a lower priority router; therefore,the other one will take over and handle all the traffic. When your router (the one that had trouble) comes back this number is added again making this your primary router.

Also, there are some commands you don't need to enter when configuring GLBP at least you are introducing a new router which will be your AVG or AVF and these commands are the forwarder preempt and glbp preempt.

Let me know if it helps.

Let me know if it helps.

jfarrer Fri, 08/11/2006 - 08:06
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I have changed the commands as you specified, but it doesn't seem to have helped. We run MRTG to graph the traffic on each router and it appears that our outbound traffic switches from router to router. It looks sporatic, we may run traffic over one router for an hour or so, then it switches to the other router for 15 minutes, then back to the first router, etc. We are using round robin balancing, so I don't know if this may be causing the issue. We can really do per host since the majority of our traffic is NAT'd to a single address. Let me know what you think.




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