Need some GLBP help please? (moved from HSRP)

[VOIPaintEASY]

I have two 7505 routers. 1 with a 10MB ethernet connection to Level III and one with a DS3 to UUnet. We use BPG to advertise our routing to the ISP's and up until now I have used HSRP to provide failover for outbound traffic to take UUnet as primary and LVLIII as backup. We have been reading about GLBP and tried it during our last downtime. The config samples I see are very simple. But, the result is we are not balancing. It either take 1 router or the other period. No balancing. Here is the configs relate to the 2 interfaces we want to balance. (Note they are the inside interfaces toward our firewalls that use 1 address that is our GLBP VIP to hand traffic off to. Are we missing something obvious?

Router #1
interface FastEthernet0/0
bandwidth 10000
ip address xxx.xxx.14.4 255.255.255.0
ip access-group IDS_FastEthernet0/0_in_1 in
no ip redirects
no ip unreachables
full-duplex
glbp 4 ip xxx.xxx.14.1
glbp 4 preempt
glbp 4 weighting 20
glbp 4 load-balancing weighted
glbp 4 weighting track 55 decrement 19
glbp 4 weighting track 66 decrement 20

Router#2
interface FastEthernet0/1/0
bandwidth 10000

ip address xxx.xxx.14.3 255.255.255.0
no ip redirects
full-duplex
glbp 4 ip xxx.xxx.14.1
glbp 4 priority 250
glbp 4 preempt
glbp 4 weighting 10
glbp 4 load-balancing weighted
glbp 4 weighting track 55 decrement 10
glbp 4 weighting track 66 decrement 10

 

[ADB100]

The load balancing is done on a per-host basis by the use of multiple virtual MAC addresses - i.e.

Host #1 ARPs for the gateway MAC address
Router #1 responds with the 1st Virtual MAC address
Host #1 sends it's packets to this MAC for traffic that needs to be routed
Host #2 ARPs for the gateway MAC address
Router #2 responds with the 2nd Virtual MAC address
Host #2 sends it's packets to this MAC for traffic that needs to be routed

If you only have 1 host (i.e. your Firewall) then all your traffic will go one way.

HTH

Andy

 

[VOIPaintEASY]

OK, that makes sense now. Can anyone think of a way we can distribute the traffic load across the two routers from the single virtual Firewall farm MAC address (which has over 2000 clients behind it) to take advantage of the outbound bandwidth of both ISP’s via the 2 routers?

 

[ADB100]

You could run a routing protocol between your edge routers and the Firewall and use Equal Cost load-balancing - i.e. inject a default route from both edge routers with the same metric and let the firewall load balance traffic outbound towards the routers. Other than that you could introduce some more routers between your firewall and the current edge routers and apply the same logic.

HTH

Andy