Detecting computers on network

[Peter Tillotson]

You could use a sniffer in promiscuous mode. pypcap -- or something 
like. This will record every packet seen by your network card. Whether 
is will work depends on whether you are on a true braodcast network.

if a box is on and completely inactive you'll never see it, but most 
boxes do something. Windows boxes positively shout about there presence :-)

baically this is pasive nmap, nmap will try to open a tcp or udp 
connection on every  machine. your going to generat a lot of traffic.

If you've got access to the boxes enabling ICMP and using that is the 
proper way.

Sandeep Arya wrote:
> Hello dear
> 
> I had sent my earlier queries regarding same topic. However just to be 
> more specific this time..
> 
> I just wann try to detect that if there are some ip address in a list of 
> some ip address alive or not.
> 
> How can i do this?
> 
> Shall i try to connect them and check that my connection is working or 
> not? If working than means alive .... (connection based)
> 
> SHalle i send some buffer value (whatever) to socket using sendto(...) 
> and then checking for return value? (Connectionless)
> 
> Well for me it doesnot matter that i should have connection or 
> connectionless.. I just wannn  know who are alive in my LAN?
> 
> This application will be for my computers in lan. not for maganetwork.
> 
> LAN will have just some bridges and computers.
> 
> i need to detect tham all..
> 
> however i doesnot matter that all of them replies or not. I just wann 
> know that atleast some of them reply. Rest i will take care of...
> 
> 
> Sandeep
> 
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