Finding Open Ports in a web server

Required Software- Nmap

Step 1: Download Nmap tool from the site www.insecure.org/nmap

Step 2: Install it in ur system.

Step 3: Go to command promt and just go to the path of the drive in which nmap is installed.

E.g:- c:\nmap>

Step 4: Now this is the command to type.

For example if u want to know about the open ports of Yahoo server.

c:\nmap> nmap -sT -p 40-225 www.yahoo.com

From the above command 40-225 are the port numbers of the server that are being checked.You can give any number of port numbers that you want , just try this one and see.
netstat -n
try this command..this will giv u all the ips along port..o r connected..
or u may try netstat -a