Command to check the open ports in Linux Server

[George]

We can use the following command to check the open ports in the Linux server but make sure that nmap module is installed on the server and if its not installed than first install nmap module by using the command "yum install nmap -y"

nmap -sT -O localhost

The above command will show you the following result.

[[email protected]~]# nmap -sT -O localhost

Starting Nmap 5.51 ( http://nmap.org ) at 2013-06-29 12:28 BST
Nmap scan report for localhost (127.0.0.1)
Host is up (0.000034s latency).
rDNS record for 127.0.0.1: localhost.localdomain
Not shown: 984 closed ports
PORT      STATE SERVICE
21/tcp    open  ftp
22/tcp    open  ssh
25/tcp    open  smtp
53/tcp    open  domain
80/tcp    open  http
106/tcp   open  pop3pw
110/tcp   open  pop3
143/tcp   open  imap
443/tcp   open  https
465/tcp   open  smtps
993/tcp   open  imaps
995/tcp   open  pop3s
3000/tcp  open  ppp
3306/tcp  open  mysql
8443/tcp  open  https-alt
10001/tcp open  scp-config