Solved: Creating gre Tunnels on a glbp enabled router

Tekena Alamina · ‎07-19-2012

Which is the best way of creating GRE Tunnels on a GLBP enabled router?

I actually have two 3845 with GLBP configured as our gateway routers, and need to create gre tunnels to branches.

The plan is to use the GLBP virtual IP as the Tunnel Source address and the branch WAN interface as the tunnel Destination address,

my issue is how do i handle the Tunnel IP address? Do i create the same Tunnel on both gateway routers and have a glbp virtual IP address

for the Tunnel Interface as well????

cadet alain · ‎07-19-2012

Why not just use the wan physical interfaces of main and branch for the tunnel on each router in the glbp group ?

Regards.

Alain.

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View solution in original post

Giuseppe Larosa · ‎07-19-2012

Hello Tekena,

it is not clear if GLBP is running on internal interface towards local clients or on the "WAN" interface towards branch offices.

In any case for better redundancy you should build two GRE tunnels from each branch router one terminated on HQ_R1 and one terminated on HQ_R2.

For this reason I would not use/reference the GLBP VIP in the GRE tunnel configurations.

In any case the GRE tunnels should be defined on both HQ_R1 and HQ_R2.

If GLBP is serving internal clients, it is likely that traffic may reach both HQ routers (when coming from different clients) so having indipendent GRE tunnels to each branch provides a better match with traffic patterns.

Hope to help

Giuseppe