ethernet Interface haywire ???

[brent]

Has anyone run into this scenario where a BSD Box (RELENG_5_4) takes down 
the whole subnet for only FreeBSD boxes. Here’s the scenario: One of my 
web servers goes into a crazy state which kills all traffic on the network 
for only FreeBSD boxes.  Linux boxes can talk to other linux boxes, but 
FreeBSD boxes are dead. You can ping a FreeBSD box (from linux) but services 
such as SSH go half-way and never completely connect. Other services such as 
http don’t work either.  Rebooting that offending box fixes the problem. 
I’ve seen this once it a great moon; however, it recently happened two 
days in a row. Any suggestions would be appreciated.  I have other 
RELENG_5_4 and RELENG_6_0 boxes that don’t seem to be the culprit, as well 
as an identical hardware box running RELENG_6_0. Thanks.