[Wylug-discuss] Semi-OT - Extending the LAN

[Jim Jackson]

On Fri, 12 Aug 2005, Seb James wrote:

> arp might have helped here, if you could have created some sort of
> communication between your pc and the faulty router. If there was any
> traffic on your network from the router, then its IP address would have
> ended up in your Address Resolution Protocol (ARP) tables. /sbin/arp
> would display these tables - the translation between the MAC address of
> the router and the IP address it had been assigned/given itself. A
> useful little program. Also, in situations like these, a non-switching
> network hub and a pc/laptop running ethereal is also enormously helpful
> - this allows you to look at all the packets transmitted on a given wire
> on your network.
>

Or more easily run tcpdump in promiscuous mode as root on a
box on the network and look for and traffic on a network other than
your normal one.