GLBP and firewall

[crazycrok]

Can anyone see any advantage of glbp over hsrp when using a pair of routers dual homed to two ISP's behind a firewall? The firewall would have the glbp IP as it's default gateway.

Looking at the load balancing modes on offer, I can't see that this would work correctly with just one host (the firewall) making use of the glbp gateway.

I would like to share the gateways and load balance the outbound traffic to the two upstream ISPs'.

Thanks,

Matt

[a-vazquez]

I think the following document will clear answer your questions on GLBP,

http://www.cisco.com/en/US/partner/products/sw/iosswrel/ps1839/products_feature_guide09186a00801541c8.html#74821

[joe.cornelson]

Hello,

This really doesn't clear the issue up. GLBP is presented as something that enables multiple hosts to be load-balanced between two or more different routers.

When you have all of those hosts going through a firewall...and that then is connected to two different routers.....the Cisco examples are broken. In this case, you have only one host going to the default gateway.

The question now becomes, Can the Active Virtual Gateway then load balance from one single host. I didn't see that happening using Cisco's documentation. Do you know for a fact that the pix, which in essence becomes a single host for the entire network is load balanced?

Thanks,

Jim Cornelson

[george]

Hi Matt,

I am looking to the same setup. Did you manage to setup GLBP with a firewall behind?Can u please provide your GLBP config?

Regards,

George G

[dgahm]

You are correct. If you only have one device (your firewall) all traffic will just use one router or the other. The firewall can only have one mac address in the ARP cache for the default gateway, so will use one router until the next ARP.

If you want to load balance in this scenario you need to use a routing protocol, or static routes.