Linux – Freeing up a TCP/IP port

linuxnetworkingporttcp

netstat -tulnap
shows me what ports are in use. How to free up a port in Linux?

Best Solution

As the others have said, you'll have to kill all processes that are listening on that port. The easiest way to do that would be to use the fuser(1) command. For example, to see all of the processes listening for http requests on port 80 (run as root or use sudo):

# fuser 80/tcp

If you want to kill them, then just add the -k option.

New answer, powershell

TCP

Get-Process -Id (Get-NetTCPConnection -LocalPort YourPortNumberHere).OwningProcess

UDP

Get-Process -Id (Get-NetUDPEndpoint -LocalPort YourPortNumberHere).OwningProcess

Old answer, cmd

 C:\> netstat -a -b

(Add -n to stop it trying to resolve hostnames, which will make it a lot faster.)

Note Dane's recommendation for TCPView. It looks very useful!

-a Displays all connections and listening ports.

-b Displays the executable involved in creating each connection or listening port. In some cases well-known executables host multiple independent components, and in these cases the sequence of components involved in creating the connection or listening port is displayed. In this case the executable name is in [] at the bottom, on top is the component it called, and so forth until TCP/IP was reached. Note that this option can be time-consuming and will fail unless you have sufficient permissions.

-n Displays addresses and port numbers in numerical form.

-o Displays the owning process ID associated with each connection.

The largest TCP/IP network port number allowable for IPv4

The port number is an unsigned 16-bit integer, so 65535.

Best Solution

Related Solutions

Windows – How to you find out which process is listening on a TCP or UDP port on Windows

New answer, powershell

TCP

UDP

Old answer, cmd

The largest TCP/IP network port number allowable for IPv4

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