Does somebody knows how to close a TCP or UDP socket for a single connection via windows command line?
Googling about this, I saw some people asking the same thing.
instant/feasible/partial answer : https://stackoverflow.com/a/20130959/2584794
unlike from the previous answer where netstat -a -o -n was used incredibly long list was to be looked into without the name of application using those ports
I found the right answer to this one. Try TCPView from Sysinternals, now owned by Microsoft. You can find it at http://technet.microsoft.com/en-us/sysinternals/bb897437
In order to close the port you could identify the process that is listening on this port and kill this process.
Try the tools TCPView (GUI) and Tcpvcon (command line) by Sysinternals/Microsoft.
https://docs.microsoft.com/en-us/sysinternals/downloads/tcpview
If you know the port that you want to free you can sort your netstat list by looking for the specif port like this:
netstat -ano | findstr :8080
Then the pid will appear at the rigth which you can kill with taskkill.
taskkill/pid 11704 /F
Also you may want to look at this question which is specifically for localhost, but I think it is relevant:
Use TCPView: http://technet.microsoft.com/en-us/sysinternals/bb897437.aspx
or CurrPorts: https://www.nirsoft.net/utils/cports.html
Alternatively, if you don't want to use EXTERNAL SOFTWARE (these tools don't require an installation by the way), you can simply FIRST run the netstat command (preferably netstat -b ) & then setup Local Security Policy to block the IP address of the user's machine in question, that's what I have been doing with unwanted or even unknown connections - that allows you doing everything WITHOUT ANY EXTERNAL SOFTWARE (everything comes with Windows)...