EIGRP Metrics

chmorin

Does EIGRP's Metrics update? Meaning, if I have a L3 switch that knows of two routes, one to 1.1.1.1 and one to 2.2.2.2, if the link to 1.1.1.1 is currently the selected route but the link degrades to the point of being almost useless but is still technically up/up, will it switch to 2.2.2.2?

I know it is part of EIGRP's compost metric, but I'm trying to figure out a way to resolve the issue. Presently we just have a default route out to 1.1.1.1 but that is obviously not the way to go if the link is shaky.

networker050184

Not by default it won't. By default it only takes cumulative delay (which does not change dynamically) and smallest bandwidth along the path. Degradation won't cause a routing change.

What you could do is something with IP SLA to monitor the link and withdraw the route.

chmorin

networker050184 wrote: »

Not by default it won't. By default it only takes cumulative delay (which does not change dynamically) and smallest bandwidth along the path. Degradation won't cause a routing change.

What you could do is something with IP SLA to monitor the link and withdraw the route.

I'm looking into IP SLA right now. I'll let you know how it goes, thanks for the suggestion!

EDIT:

So I see how I can get IP SLA to monitor the link and send an SNMP trap if it violates a credential, but I have no idea how to take that and turn it into a changed route. =/