Load balancing with EIGRP and the Variance command

voiper_99 · ‎05-23-2007

Hi, I have set up a small lab with a few 877 and 837 routers and have set up load balancing via EIGRP and the variance command and now I just want to make sure that it is working as desired but I am not too sure how to do that. I have tried access lists and debugs but they haven't really given me a straight forward answer. Is there any show/debug/other command designed specifically to show you if/how load balancing is working?

Thank you in advance.

Amit Singh · ‎05-23-2007

"Show IP route " will tell you if you have all the routes listed as desired for a particular destination. You can use " show IP EIGRP topology " command to see the feasible successor for a particualr destination route. Check the Metrics advertised by the neighbors. EIGRP should meet the " feasability condition " to do the equal/unequal cost path load-balancing. Check the Feasible distance for a particular destination and then use the varience number to multiply it with the FD to have all the routes eligible for load-balancing.

Please see the link below:

http://www.cisco.com/warp/public/103/19.html

HTH,Please rate if it does.

-amit singh

voiper_99 · ‎05-23-2007

Thank you for the quick reply.

To give you a better understanding of what I am trying to do, here is a snippet of the topology table:

P 10.1.6.0/24, 1 successors, FD is 1280512, serno 257

via 192.168.4.2 (1280512/1277952), Vlan4

via 192.168.5.2 (1688576/1686016), Vlan5

What I am wanting to do is get traffic destined for the 10.1.6.xx network to be load balanced across both 192.168.4.2 and 192.168.5.2.

In regards to your comment here, "Check the Feasible distance for a particular destination and then use the varience number to multiply it with the FD to have all the routes eligible for load-balancing. " What variance numeral will I need to get load balancing working here?

Also, in regards to the line - via 192.168.4.2 (1280512/1277952), I know the first number in parenthesis is the feasible distance, but what is the second number? The advertised distance?

Amit Singh · ‎05-23-2007

Yes, the second number is the Advertised distance by the neighbor router.

The varience value of 2 should be able to make the desrired results.

Conf t

Eigrp 10

varience 2

Once the Varience is configured, Please clear the route using the command " clear ip route 10.1.6.0" and the EIGRP will run the route again and will start using all the avialble paths for unequal load-balancing.

HTH,Please rate if it does.

-amit singh