Load Balancing

[baig]

Hi all,

We have two links to each remote site via DDN & IP VPN Over Mpls, running EIGRP & BGP respectively. I need to start load balancing. I thought of configuring it thru "backup interface command" but arent sure weather its gonna work efficiently. Would appreciate if I could know abt a better option.....Thnx

[ruwhite]

Hmmm.... The problem here is that you're running two different routing protocols over the two different links. There's not much of a way to load share unless you can figure out how to get the same protocol on both links. I suppose you could replace EIGRP with BGP, and do a lot of redistribution, but then you're going to have to do some special things to make BGP load share, since BGP will normally only install one route in the local routing table.

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094431.shtml

Will give you more information there. This is one of the reasons we press on the providers to support EIGRP PE/CE and OSPF sham links.

:-)

Russ.W

[Richard Burts]

To supplement the correct explanation that Russ gives, if you use the backup interface command it will not load balance at all. Backup interface puts the backup interface in standby mode and it will not transmit any data until the primary interface is protocol down. So if load balancing is what you want to accomplish then backup interface would be counter productive.

HTH

Rick

[baig]

I think if i use backup interface command along with "backup load 25 5" or the "backup load threshold either" command. then the secondry interface will be up when the primary link is utilized 25% or what ever i feel is neccessary.

Well, frankly speaking i myself is apprensive about this configuration!!!

i was even thinking of manipulating with AD of both protocols and/or configure static routes with AD of BGP i.e., 20

>>> Nyhow i appreciate both of urs responses.......& looking forward for comments on my present idea

[Richard Burts]

You are correct that backup load should bring the backup interface out of standby mode when the load is larger than the threshold. It still leaves the challenge of getting the router to use both links if the destination addresses are learned by different routing protocols.

HTH

Rick