On Wed, 2007-01-03 at 15:47 +0100, Mogens Kjaer wrote:
> This question is way off topic, sorry. I have googled and
googled and have
> not come up with a answer to my question.
> I want to query a switch (via SNMP I think) to get a list of systems
> attached to it. I am using Nagios and would like to determine
> dependencies. Trace route will not work because it will not show
> routers/switches for systems on the same sub-net as the system doing the
> trace route and I have seen where it does not return the network based
> switch a system is attached to, just the router. If I could get a list
> systems attached to a router/switch (not a personnel switch, a managed
> switch) I can correlate the information and build dependencies. I have a
> hand-held Fluke network tester than runs Linux that will do this for me
> I type in a hostname, I would rather do it programmaticly because I have
> over 300 systems I need to do. I am open to any method that works that I
> can script so I don't have to do it every time a new system appears. Just
> in case it matters some systems are attached to a V-lan off a managed
> and I do NOT have admin rights to the routers or switches.
I wrote a C program that uses SNMP for this.
It queries the switches and hubs for the MAC addresses
seen at each port and the number of bytes in/out.
Some switches have a MAC to IP table, else I would
ask the ARP table of the router for a table like this.
) does this if you enable
The program then prepares a nice top-10 on the
intraweb showing which computers are generating
most traffic, and another table with traffic
at each switch/hub port.
) will do nice summaries of traffic
by hosts/ports/whatever for whatever systems are bridged
to the collecting port.