FreeBSD Router and ARP (fwd)

Dan Mahoney, System Admin danm at prime.gushi.org
Thu Jul 10 12:04:15 PDT 2003


I have a lan of maybe 200 nodes where a BSD box is performing as the
core router (with cisco's doing line-connectivity).  It is all switched,
with no VLAN in place.

Each machine (in general) has its own subnet.  Most are /29's, some are as
large as a /25.  Each subnet has a single gateway ip configured on the
router.  This is so that each machine can have a gateway within its own
subnet.

This works reasonably well, except that when running ethereal on one of
the local machines, I discovered an alarming rate of ARP requests coming
out from the MAC of the BSD router.

Considering the arp is supposed to be cached for 20 minutes or more until
something different is heard, I shouldn't see five or six requests within
two seconds.

I don't see this when routing with (say) a Cisco router.  Is there some
reason for this?

TCPDumps from my local desktop available upon request.

-Dan Mahoney

--

"There is no right and wrong, there is only fun and boring."

-Fisher Stevens, "Hackers"

--------Dan Mahoney--------
Techie,  Sysadmin,  WebGeek
Gushi on efnet/undernet IRC
ICQ: 13735144   AIM: LarpGM
Site:  http://www.gushi.org
---------------------------





More information about the freebsd-isp mailing list