[Beowulf] Is it necessary to increase size of the ARP cache?

[Greg Lindahl]

On Thu, May 27, 2010 at 05:25:56PM -0500, Rahul Nabar wrote:

> But is there a way of knowing from logs etc. if this fix is indeed needed
> for my network?

If you tcpdump and see a crapload of arp broadcasts, you know.

> What is the effect of a suboptimal ARP cache size? Does that affect
> the latency of messages too?

It hurts latency because an arp reply has to come back before you can
send your packet.

-- greg