Load Balancing

[rodnei.magalhaes]

Hi.

I have two 256K links and one of them I am updating to 1 Mbps.

Some friends told me that I can have problems to load balancing links with different bandwidth.

I would like to give more information about this scenario.

Thanks.

[thisisshanky]

Easy way to do this is to use two default routes with same cost and if your router supports CEF, enable CEF.

Sankar

PS: please remember to rate posts!

[ankurbhasin]

Hi Rodnei,

Load balancing on different bandwidth links may be a mind game when you are running routing protocol like EIGRP which uses bandwidth as a major component for route calculation.

But incase you are not using any routing protocol you can simply have 2 defaut routes with same admin distance whch will do equal load balancing.

ip route 0.0.0.0 0.0.0.0

ip route 0.0.0.0 0.0.0.0

HTH

Ankur

[Harold Ritter]

Just having two static routes will send the same amount of traffic on the two links, which will certainly cause issues if your aggregate traffic goes over 512Kbps.

EIGRP does support unequal cost path loadbalancing via the "variance" command.

For more information on unequal cost path loadbalancing support in EIGRP, refer to the following URL:

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008009437d.shtml

Hope this helps,

[rodnei.magalhaes]

Thank you for your help.

I have one more question: the OSPF protocol has the same "variance" command?

[pkhatri]

Hi,

Unfortunately, OSPF does not support unequal-cost load balancing, and does not have a variance command.

Paresh

[Harold Ritter]

The only other way I know to do unequal cost path loadbalancing is by using MPLS TE. But this is another story ;o)

Hope this helps,