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New Member

GLBP and round robin


I'm having a bit of problems with getting GLBP to work in a round robin fashion and was wondering if anyone could help.

I have two CE's with GLBP configured on their LAN interfaces and a switch connecting the two which I am also using as the client.

My GLBP configuration is as follows:

on CE 1

glbp 10 ip

glbp 10 timers 1 5

glbp 10 timers redirect 2 602

glbp 10 priority 110

glbp 10 preempt

glbp 10 weighting 100 lower 95

glbp 10 authentication text yyyy

glbp 10 weighting track 11 decrement 10

CE 2

glbp 10 ip

glbp 10 timers 5 18

glbp 10 timers redirect 10 610

glbp 10 preempt

glbp 10 weighting 100 lower 95

glbp 10 authentication text yyyy

glbp 10 weighting track 11 decrement 10

Track 11 is just an SLA monitor doing an ICMP echo across the WAN /30.

My intention is for CE1 to be the Active Virtual Gateway yet have both CE's acting as Active Virtual Forwarders.

My understanding is that with no load balancing method specified it will default to round-robin (confirmed with sh glbp command).

Therefore when devices behind send arp requests for the shared IP they will receive different virtual MAC's .

Attached is the output of the sh GLBP command on both routers:

However when I go to the switch clear the arp table, then do a ping and view the arp table I always get the same MAC address and its the virtual MAC of the AVG.

If the track fails and CE2 becomes the AVG then I get CE2's vrtual MAC address.

It doesn't seem to be actually load balancing.

Anyone know what the problem may be?

It could very well be my understanding of GLBP. Maybe by doing a clear arp on the switch I'm actually re-setting the round robin counter so everytime it tries to connect its just getting the first in the round robin.

Any thoughts would be great :)


New Member

Re: GLBP and round robin


it will not load balance. I think mainly because you didnt tell it to load balance in the first place.You need

glbp 10 load-balancing weighted

on the two routers, to the best of my understanding round-robin and host-dependent will only allow u use one link at a time. default is round-robin but it more of randon then any other thing.u can also tell the routers to load-balance with round-robin or host-dependent.

Pls let me know if it works. I have issues with glbp myself but not the one you are having