looking for the port and server.

bruse · 10-07-2005, 06:29 AM

HI ALL,
(suse 9.3/mandrake 10.0/debian 3.1)
I have connected to the internet via proxy server in my network.Some times it seems that the above server is up but the port (default 3128)is not open.i mean the port is closed.So the connection is refused to contact a www.google.com or what ever.So my question is how can i find the port number for which they are providing the internet facility and on which server.i think it is possible using nmap.But i do not know how to look.Or any other command or software for linux?

thanks,
bruse

thobck · 10-07-2005, 07:34 AM

Hi bruse,

One question: how can you see that proxy is up? Be carefull on using scripts to see that...

"lsof -i " is a good tool to see the relation between open ports (their file descriptors) and processes.

regards,

Thomas

bruse · 10-08-2005, 01:04 AM

yes really a good think.
see i am working in a proxy server environment in my university.So that i know the ip address of that system.so i can check whether it is up or not using "nmap"
and i can see the open ports also.In a same way looked there and it was closed

So any guess...how to the port number of the real internet connection and server IP address.