How to check and open ports in Linux
The most common host-based tool for checking for open ports on Windows or Unix systems is the netstat command.
To see open TCP Network Ports :-
vishal@vyas:~# netstat -vatn
To see DNS Hostnames :-
vishal@vyas:~# netstat -vat
To see open UDP Network Ports:-
vishal@vyas:~# netstat -vaun
===================================================================
Nmap (“Network Mapper”) is an open source tool for network exploration and security auditing. Nmap can provide further information on targets, including reverse DNS names, operating system guesses, device types, and MAC addresses.
vishal@vyas:~#nmap -sS 10.10.10.50
Starting Nmap 4.53 ( http://insecure.org ) at 2011-12-26 12:35 IST
Interesting ports on vishalvyas.com (10.10.10.50):
Not shown: 1703 closed ports
PORT STATE SERVICE
22/tcp open ssh
80/tcp open http
110/tcp open pop3
111/tcp open rpcbind
139/tcp open netbios-ssn
143/tcp open imap
445/tcp open microsoft-ds
993/tcp open imaps
995/tcp open pop3s
3306/tcp open mys…
To see open TCP Network Ports :-
vishal@vyas:~# netstat -vatn
To see DNS Hostnames :-
vishal@vyas:~# netstat -vat
To see open UDP Network Ports:-
vishal@vyas:~# netstat -vaun
===================================================================
Nmap (“Network Mapper”) is an open source tool for network exploration and security auditing. Nmap can provide further information on targets, including reverse DNS names, operating system guesses, device types, and MAC addresses.
vishal@vyas:~#nmap -sS 10.10.10.50
Starting Nmap 4.53 ( http://insecure.org ) at 2011-12-26 12:35 IST
Interesting ports on vishalvyas.com (10.10.10.50):
Not shown: 1703 closed ports
PORT STATE SERVICE
22/tcp open ssh
80/tcp open http
110/tcp open pop3
111/tcp open rpcbind
139/tcp open netbios-ssn
143/tcp open imap
445/tcp open microsoft-ds
993/tcp open imaps
995/tcp open pop3s
3306/tcp open mys…
