How do I find out what ports are listening/open on my Linux/FreeBSD server?
There are different commands on both Linux and UNIX server to find out what tcp/udp ports are listening or open on your own server. You can use netstat command, which print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships etc. Another (and suggested) option is to use lsof command, which list open files, and ports on Linux, FreeBSD, Solaris and other Unixish systems.
netstat Command Example
# netstat --listenDisplay open ports and established TCP connections:$ netstat -vatnFor UDP port try following command:$ netstat -vaunIf you want to see FQDN, remove -n flag:$ netstat -vat
lsof Command Examples
Display list of open ports
# lsof -iTo display all open files, use:# lsofTo display all open IPv4 network files in use by the process whose PID is 9255, use:
# lsof -i 4 -a -p 9255
Subscribe to our free e-mail newsletter or RSS feed to get all updates.
You can Email this page to a friend.
Related Other Helpful FAQs:
- OpenBSD Install Ports Collection
- How do I install and search FreeBSD ports or a package?
- Linux: Find out which network card or NIC server is bind or running on
- What ports need to be open for Samba to communicate with other windows/linux systems?
- Linux port scanning with netcat (nc) command
Discussion on This FAQ
Leave a Reply
We encourage your comments, and suggestions. But please stay on topic, be polite, and avoid spam. Thank you very much for stopping by our site!
June 22nd, 2007 at 9:43 am
I used lsof command in freebsd 5 i am not getting any output for checking tcp/udp ports which are listening or open on my server
June 5th, 2008 at 11:27 am
What is the equivalent port for com9 on linux?How do i find out com port equivalents in linux?Thanks