discovering network layout at layer2

From: Dev (u02113@cs.unipune.ernet.in)
Date: Fri Feb 06 2004 - 11:27:21 EST

('binary' encoding is not supported, stored as-is) Hello ppl,

I am new to this list. Plz redirect me to another list if this is not the appropriate list to post to this query.

Having read the phrack article "Fun with the spanning tree protocol", I was wondering as to how i could use some layer2 protocols to my advantage to discover the network layout of my campus network (at layer 2).

Additionally, all equipment is CISCO.

Identification of my nearest switch is easily done by sniffing for STP BPDU packets & i did receive the STP hello BPDU packets on the user port that our gateway was connected to. This kind of packet gives me the following information:

1) How many more STP -capable devices are there up to the root bridge (root path cost)

2) The bridge & port ID & the root bridge & port ID.

Can somebody suggest how can i find out my network topology using this STP protocol or some other layer2 protocol (CDP?? etc).

regards,
Devrat Mittal
u02113@cs.unipune.ernet.in
Department of computer Science
University of Pune
Pune.


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