OSPF load-balance unequal paths

[rainman]

Hello,

I know that OSPF can not load-balance over un-equal paths, but what happens when you try to do this?

I have a scenario where a OC-3 interface and also a Gig-E interface are setup as P2P links. Each have an OSPF cost of "1". What happens when the OC-3 interface reaches 100% utilization?

Reason I'm asking this is I'm seeing discards/drops on my new Gig-E interface, and I was wondering if OSPF will start dropping packets on the "bigger" interface when the OC-3 hits 100%.


Rainman

 

[gwildfire]

by default the metric system for ospf treats 100mps as 1, so as far as ospf is concerned you have two equal paths. So you could implement load balancing, but it wouldnt be wise.
You need to change the reference bandwidth to resolve this.
Chances are you are sturating your oc3 as 155mps and 1Gb is a fair difference.

As an alternative could you implement something like policy based routing? allowing some customers to use the oc3 and some the Gig interface?

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