Do Applications make use of the same Port Number or Different Ports for concurrent connections?

Question

Do applications make use of different local ports for concurrent connections or is it the same port number that is being used for the second new connection? For example if i open My Firefox Browser (on port 57615) and i want to open another Firefox application (i.e. 2 concurrent applications running now). Will Both applications run on Port 57615 (example port) or will the second Firefox application be assigned a different local port (e.g 5766)?

(i.e I opened Firefox Application and I opened another Firefox Application)

Using the command below shows it's using the same port Number for both Concurrent Applications BUT I would Like to be VERY SURE!!!

netstat -ano |find / "firefox.exe"

netstat -ano |find / "process id"

Cheers

Answer 1

Firefox doesn't use one port, it's a client application so every time it initiates a connection it asks for it to the Operating System, the latter assings a different port number for every connection.

So, it doesn't matter how many Firefoxs you opened but how many connections each Firefox initiated, each connection will have a different local port.

Perhaps you get the same port every time you use Firefox because it is returning the resources to the operating system when you close it and the new execution it's getting the same port.