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New Member

Multiple GLBP groups in one subnet

Hi All,

I have read all I can on GLBP without a definitive answer to my question. I have two 7613 routers connected to two 7304's that serve as our gateways to the ISP. I would like to run these connections through a 6509VSS and run GLBP on all 4 routers in the following manner.

I would like to connect 4 routers to the VSS, place their interfaces into the SAME subnet but running a different GLBP group as below

7613:                                       Virtual IP  for Group 1                   7613:       GLBP 1 IP 172.30.100 66    

            X                                                                                 X

              X                                                                            X

              VSS Layer 2 only and used to connect all devices into the same vlan 2010

                X                                                                          X

              X                                                                               X        GLBP 2 IP  

76XX:                                         Virtual IP for group 2                  76XX:

The subnet is ( .65 - .78 )

My question is whether the two groups of GLBP instances can coexist within the same subnet using 4 routers. My goal is to have one gateway address for each side. The 76XX routers represent the AT&T routers facing their MPLS network. I want to do load balancing across those routers for outbound traffic and my 7613's to load balance the return traffic.

I am running GLBP in my core between the two 7613's and multiple 3750me switches that provide a very high level of redundancy. I'm just not sure if the scenario above is supported.

Thanks for any and all comments or suggestions.


  • LAN Switching and Routing
New Member

Re: Multiple GLBP groups in one subnet


Since first posting this question, I have coded the design in a lab and the design works as drawn. This provides gateway protection to an ISP in both directions.

New Member

I was just wonder this same

I was just wonder this same thing. Thanks for the post, very helpful!

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