Erich Meier Erich.Meier at
Mon Sep 29 14:33:00 UTC 1997

> Scott,
> One method to detect duplicate IPs is to use SNMP to query your routers
> every 4 hours for the ARP entries. (ARP times out every 4 hours in a cisco
> router)  We use the CMU snmp package to do the queries.  Then put the info
> into a database and query the database for duplicates.  We have a system
> like this with a web interface and also some scripts that scan ths
> database daily for duplicates and e-mails notices to people in charge of
> the relevant subnet.
>   The code is somewhat rough, so I do not want to offer it to the
> net-at-large.  If you can not find a polished product, e-mail me and I'll
> share more aobut this solution.
> Art.
> On Mon, 29 Sep 1997, Scott wrote:
> > Alittle off subject but does anyone out there know of some SW that detects
> > duplicate IP addresses?
> > 
> > Scott
> > 
> > 

I think you are searching for arpwatch. Source can be found at

It needs libpcap to run but that can be found also at this location.

Have fun,
Erich Meier	                         Erich.Meier at
 "The truth is not out there. The truth is not out there. The.." - Bart Simpson

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