RE: mac addresses

["Joyce, Matthew" <MJoyce@ccia.org.au>]

> 
> On Sun, 2003-07-27 at 20:16, Joyce, Matthew wrote:
> > Does anyone know of a tool or util which can list all the mac 
> > addresses being used on a lan ? I'm trying to discover if foreign 
> > devices are being connected over the weekend.
> > 
> > Ideally I'd like to be able to compare one list with 
> another and see 
> > the difference.
> You have to have a node on the segment you want to watch, and 
> then use "arp"
> 
> It has a few variations of usage, but should be able to cover 
> your needs.
> 
> 

Thnaks Grep.

Yes it is a fairly simple network.

I was going to run

nmap -sP x.x.x.*
arp -a | grep ether |awk '{print $4}'

This give me a nice list.

but as for scanning this list for entries not included in another list I am
a bit stuck...

...arpwatch reads like it will do this very well.

thanks everyone