Oftentimes when debugging some form of online service on Linux if can be handy to know what ports are currently open on the system you are working on. Back “in the day” we got this functionlity via netstat. Unfortunately that has now been deprecated so how do we achieve this.
In short ss
Will generate similar output to the netstat command and with the -p command you can see the process id that has bound to the port as well.
I recommend using man ss for information on what all the command switches do.