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GLBP host-dependent details

Hello,

 

I've got following scenario inherited:

Two routers R1 and R2 running GLBP round robin mode currently.

Three clients (C1, C2, C3) only.

All the clients are Up all the time sending data through the GLBP virtual IP address used as their default GW.

The behaviour observed is:

Each client is swapping his physical default GW per 4 hours.

 

My understanding is: GLBP round robin is replying to ARP requests alternating the two forwarder MAC addresses.

So when C1 default GW ARP entry expires (after 4 hours by default), C1 sends an ARP requests and receives R1 (e.g.) as the forwarder.

Then C2's default GW ARP entry expires and C2 receives R2 as the forwarder.

C3 receives R1 finally.

C1's GW ARP entry expires (after another 4 hours) and C1 receives R2 as the forwarder.

So C1 changes the physical default GW per 4 hours!!

(Which is valid for any odd number of clients in the group.)

 

I'd like the clients to keep their physical default GWs.

So GLBP host-dependent mode might be the solution here?

 

But the only details I found on Cisco web are:

"Use the host-dependent method of GLBP load balancing when you need each host to always use the same router."

My understanding is the forwarder is assigned to the client based on same hash computed from the client MAC address?

But I'd also like to assure C1 will use R1 as his default GW as long as R1 is alive.

And C2 will use R2.

 

Is there any way to configure such details in IOS?

Or will I have to move from GLBP to MHSRP here?

 

Thanks,

Milan

 

 

 

 

 

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