determine network topology
 

hi all.
i've been given a project recently concerning about networking and programming on linux. and this project will involve sniffing the network traffic and gathering the source and destination IP addresses. From this data, this program should determine the existence of LAN segments and construct the resulting network topology. So my question to you all is that, Do you have any idea how to achieve this? could anyone give me a brief step by step guide on how to do it?

my guess is,
1.first you need to open the network card in promiscuous mode (what command to use in linux? and how?).
2. sniff the network traffic and gather all the source and dest ip address (what command to use?? how to list all the source and dest ip out??).
3. analyse the net mask and determine the topology.


thanx in advance for any input

I'm getting a vision.....I see you and Ethereal becomming fairly intimate in the very near future :)

thanx you for the reply Zeos.
i've looked at ethereal, but their code is not in java and abit too confusing. So could anyone give me a step by step guide to do it in linux??

like you show me how would you do it using command in linux. or just convert these steps into linux command. so i will try to convert all those steps into java code.

1.first you need to open the network card in promiscuous mode (what command to use in linux? and how?).
2. sniff the network traffic and gather all the source and dest ip address then output it(what command to use?? how to list all the source and dest ip out??).

please help. coz this is a major project and i'm not familiar with linux at all.

Look at tcpdump. You can direct that output to a file for analysis. Type "man tcpdump" to learn more about it.

Ethereal has a command line version called tethereal