Network monitor

[John Hearns]

On Wed, 19 Nov 2003, James Kosin wrote:

> 
> 3)    Some switches may have ways of monitoring network activity.  Don't ask
> me witch ones..... I really don't know.

I at first thought Peter was wanting to do dicovery of routers.
Discovery of switches is of course a lot harder.

You are talking about unmanaged switches here.
In order to do a discovery, you need an SNMP  managed switch (or 
switches).
A snmpwalk of the switch will give information of the MAC addresses
attached to each port.
You match up the MAC address with the IP of the host - or a downstream
switch of course - in order to build up the topology.
I'm of course assuming that the hosts are on the same subnet as you,
so an arp will get you the MAC/IP pairing.

I think this is going off-topic for this list.