Need to know how many connections i have on a specific port. using netstat

You can use

netstat -pnlt | grep ':portno'

another option , you can use nmap tool for checking open ports on the server

nmap -sT -O localhost

Output

Starting nmap 3.55 ( http://www.insecure.org/nmap/ ) at 2004-09-24 13:49 EDT
Interesting ports on localhost.localdomain (127.0.0.1):
(The 1653 ports scanned but not shown below are in state: closed)
PORT      STATE SERVICE
22/tcp    open  ssh 
25/tcp    open  smtp
111/tcp   open  rpcbind
Device type: general purpose

Netstat Example :

[root@krizna ~]# netstat -pnlt | grep ':80'
Proto Recv-Q Send-Q Local Address               Foreign Address             State       PID/Program name 
tcp        0      0 :::80                       :::*                        LISTEN      1164/httpd          

Use netstat -natpe.

From the man page:

-e, --extend
 Display additional information.  Use this option twice for maximum detail.

As clear as mud.

Which will add two columns, User and Inode to the display.

Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address               Foreign Address             State       User       Inode      PID/Program name
tcp        0      0 0.0.0.0:3306                0.0.0.0:*                   LISTEN      100        13119      1901/mysqld