Some other stations are trying to access the IP addresses marked as
incomplete,
therefore the router tries to arp for them. Because the stations do not exist
on your network, the arp request is not successful. i would setup 'logging
accesslists' inbound on the other interfaces of the router to track where
the requests come from.
hth
Reinhold
On Fri, 11 May 2001, Valeri Marinski wrote:
> hi group
> i have some strange entries in the arp cache of all our 7200 routers
> with "Incomplete" MAC
> here an example of "sh arp":
>
--
>
> Internet 172.16.90.232 0 000c.8323.c5d2 SNAP
> TokenRing1/2
> Internet 172.16.90.233 0 Incomplete SNAP
> Internet 172.16.10.166 0 Incomplete SNAP
> Internet 172.16.90.246 0 4005.002d.7160 SNAP
> TokenRing1/2
> Internet 172.16.10.167 0 0800.09c4.8884 SNAP Fddi0/0
> Internet 172.16.100.201 0 0006.0d5c.db9f SNAP
> TokenRing1/3
> Internet 172.16.90.247 0 .8322.1515 SNAP
> TokenRing1/2
> Internet 172.16.90.244 0 .8329.bc8d SNAP
> TokenRing1/2
> Internet 172.16.100.202 0 0008.c13a.6ba1 SNAP
> TokenRing1/3
> Internet 172.16.10.164 0 0800.09c4.e844 SNAP Fddi0/0
> --
>
> Internet 172.16.80.363 .8323.88e3 SNAP
> TokenRing1/1
> Protocol Address Age (min) Hardware Addr Type Interface
> Internet 172.16.10.127 3 .5a42.6d48 SNAP Fddi0/0
> Internet 172.16.20.980 Incomplete SNAP
> Internet 172.16.10.124 3 .5a42.6d48 SNAP Fddi0/0
> Internet 172.16.20.990 Incomplete SNAP
> Internet 172.16.10.125 3 .5a42.6d48 SNAP Fddi0/0
> Internet 172.16.80.323 .8327.e9ad SNAP
> TokenRing1/1
>
>
> as you can see there is no interface behind and the age remain 0
> those ip addresses were/are not in use
>
> all our users have Olicom token ring cards (.83) and they are all
> patched to Alcatel TR concentrators some are connected to Bay TR
> switches - but in both cases you can see this strange arp entries
> if i clear the arp cache - those entries apper again and they vary
> i don't know if it is a problem - i can't see any performance problems
> what could this be?
> cabling reflections?
> any comments are appreciated
> thanks in advance
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=4178&t=4164
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