[nsp] Ethernet MAC address of value zero

From: Gert Doering (gert@greenie.muc.de)
Date: Mon Nov 12 2001 - 07:30:55 EST


Hi,

one of our switches is spewing the following message at me:

Nov 11 23:46:48 switch 2001 Nov 11 22:08:06 %SYS-4-P2_WARN: 1/Filtering Ethernet MAC address of value zero from agent host table interface
Nov 11 23:47:19 switch 2001 Nov 11 22:08:37 %SYS-4-P2_WARN: 1/Filtering Ethernet MAC address of value zero from agent host table interface
Nov 11 23:47:39 switch 2001 Nov 11 22:08:57 %SYS-4-P2_WARN: 1/Filtering Ethernet MAC address of value zero from agent host table interface

(in regular intervals, 4000 lines per day).

The message itself is clear to me, but...

 - it started when I upgraded *another* switch in the LAN, a Cat5000/SupII
   from 4.something to CatOS 5.5(11).

   What could be the reason?

 - is there any procedure to track which machine is generating these
   packets? For obvious reasons "show cam ..." won't work, and "just
   unplug one port after each other until it stops" is not workable
   either (MANY switches).

 - I tried tcpdumping, but it is not a broadcast, so I didn't see it -
   and I can't just SPAN everything to a monitor port as it's just too
   much traffic. What I will try (unless someone suggests a better
   approach) is to span each port of the 2948 in question in turn, but
   that's not a perspective that makes me very happy...

Suggestions welcome,

gert

-- 
USENET is *not* the non-clickable part of WWW!
                                                           //www.muc.de/~gert/
Gert Doering - Munich, Germany                             gert@greenie.muc.de
fax: +49-89-35655025                        gert.doering@physik.tu-muenchen.de



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