[Beowulf] Network problem: Why are ARP discovery requests sent to specific addresses instead of a broadcast domain

Rahul Nabar rpnabar at gmail.com
Mon Jul 12 21:04:48 PDT 2010

I am puzzled by a bunch of ARP requests on my network that I captured
using tcpdump. Shouldn't ARP discovery requests always be sent to a
broadcast address?

I have requests of the type below which seemingly are addressed to a
specific mAC address.

00:26:b9:58:d7:2f > 00:26:b9:58:eb:b8, ARP, length 42: arp who-has tell
00:26:b9:58:eb:b8 > 00:26:b9:58:d7:2f, ARP, length 60: arp reply is-at 00:26:b9:58:eb:b8

Now if mumble:d7:2f already knew that mumble:eb:b8 was
(which it indeed is) then why would it send out an ARP discovery
I can see that something doesn't make sense here but I cannot figure
out what is causing the problem. Any ideas? Has anyone seen this


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