MLPPP load balancing with diff BW serial links

JHolmes763 · ‎12-21-2008

Hi. I'm looking to find out how multilink PPP will load balance across serial links that have different amounts of bandwidth. One serial link is 2048 and the other is 5120.

Is the load balancing going to be a straight round-robin? Won't that create a higher utilization on the 2M link verus the 5M?

Thanks for any info.

Giuseppe Larosa · ‎12-22-2008

Hello John,

multilink PPP is not the right tool in your scenario.

You should divide the faster link in two subinterfaces (easy with Frame-Relay) and then to perform load-balancing over the three logical links using IP load sharing.

Another option is to have them as distinct layer3 links and to use EIGRP capability to perform weighted load balancing over unequal cost links (if applicable)

Hope to help

Giuseppe

JHolmes763 · ‎12-23-2008

Giuseppe,

Thanks for the tips on this. The two links are satellite connections between BGP peers. Straight serial, so I don't believe we can divide it up into subinterfaces.

The point is kind of dead anyhow, since we couldn't get MLPPP working between the two routers. MLPPP would come up, BGP would come up, but the ML interface would take nothing but errors. Links run clean on their own.

We ended up just running two BGP connections between the routers and splitting up some advertisements to balance the links.

Thanks again for the assistance, though. :)

-John