GLBP on multiple interfaces?

[deveynFSM]

Is it possible to run GLBP on more than one interface on a router?

We have two 7204Vxr connecting to two Catalyst 3560s in a fully meshed configuration and would like each 7204 to run GLBP and have a second GigE interface for redundancy.

I've gotten this working with a 3845 router using switch ports and a VLAN interface, but am not able to find any documentation on how to use more than one routed interface like in our proposed configuration.

The current GLBP group is running on a subinterface and is dot1q encapsulated, i.e. interface gig0/1.40

Any help would be appreciated.

[Giuseppe Larosa]

Hello Dan,

each router can have only one interface in a given IP subnet.

The only way to provide link redundancy would be to use integrated routing and bridging IRB but it may not work well with subinterfaces

bridge 1 protocol ieee

bridge 1 route ip

int f0/0

no ip address

bridge-group 1

int f0/1

no ip address

bridge-group 1

interface BVI1

ip address x.x.x.x 255.255.255.y

! GLBP commands here

note:

only one link will be up and STP 802.1D legacy is runned on the router interfaces (bridge 1 protocol ieee)

the other link will be in STP blocking state.

The router will interact at STP level with switches so ensure that the switches are the primary and secondary root bridge for each vlan.

Some platforms may support the use of bridge-group under a vlan subinterface, you should check this on your devices.

Most of GLBP / HSRP designs use an H schema with a single router link and an horizontal L2 link between LAN switches.

Hope to help

Giuseppe