Harping on ARP [LWN.net]

Harping on ARP

Posted Aug 22, 2003 0:16 UTC (Fri) by tmattox (subscriber, #4169)
Parent article: Harping on ARP

I researched this Linux ARP problem/feature over 3 years ago when building our KLAT2 cluster supercomputer. It has 4 NICs (each with unique IP addresses) in each node, and ARP was just messing up all over the place. Luckily, the sysctl arp_filter, though tersely documented, seemed to resolve most of the problems at the time. Ultimately, I just preloaded the ARP caches with the proper entries and left it at that.
I do hope the current discussion on the mailing lists will find a solution amenable to everyone. I advocate a sysctl switch for "Set the source IP address of an ARP request to that of the sending NIC", but of course I'd have more influence if I posted patches to accomplish that... too bad the neighbor code (ARP) in Linux is larger than I care to rummage through today.
-- Tim

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