load-balancing t1s

Feb 16, 2007 2 Replies

I have two point-to-point t1 lines, with a 1720 and a 2621 on the ends. I was under the impression that by simply having routes of equal costs going through both t1s, that packets would be spread among them, at least to some extent.



However, in practice it doesn't work that well. Any one host only seems to be able to use a max of about 1.5mbits, and even with multiple connections from various hosts, I never get to more than about 2.0 or 2.3 mbits total throughput. Looking around, I see that nearly all references to load-balancing t1s as using CIF, and our feature set (or IOS version) doesn't appear to support the commands that they utilize.



So... any suggestions about how to make this work?



Jasper



ha scritto nel messaggio news: snipped-for-privacy@v33g2000cwv.googlegroups.com...

Hi,

if you do not use CEF you're probably using fast switching which supports only per-destination/flow load-balancing. CEF can do per-packet load-sharing.

A better solution can be MLPPP ( MultiLink PPP ) between the two links.

Regards, Gabriele

The 1700 and 2600 support CEF, but they do not do per-packet load-balancing using CEF. If you turn off CEF (and process switch) the packets will load balance the T1's buy you will kill both routers due to CPU and be lucky if you get more than 1.5Mbps total throughput. The only way to do this is with MLPPP.

Scott

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