Single IP routing problems through Level3
Matthew Kaufman
matthew at eeph.com
Sun Jun 15 22:07:21 UTC 2008
Matt Palmer wrote:
> A multiple-link bundle which is load balanced by source/destination pair
> with an undetected dud link? I hadn't thought of that, but it does make an
> *awful* lot of sense....
I've also seen interesting OSPF misconfigurations that resulted in a
router doing path-wise load balancing between the live link and an
unroutable destination address that went into the bit bucket.
On the Cisco boxes I was using at the time, the hallmark of
load-balancing into a dead path was that every other IP address worked,
but then every some number of addresses (12, as I remember, but I'm not
100% sure) the polarity flipped, so that whichever of odd vs even had
worked before was now the one that didn't for the next N addresses.
Artifact of the hash algorithm in use, no doubt.
Matthew Kaufman
matthew at eeph.com
http://www.matthew.at
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