Port Forwarding - close it or not??

I recently found myself in need of using static private ip for my port forwarding needs. However, I noticed that the little computer network connection icon in the system tray keep flashing signaling packets are being sent and received constantly, even when I am not using the application which requires port forwarding. I then went to close that port, and everything was back to normal.

Now, I am not sure what is the best way to do this. Does that packet sending and receiving effect system performance? Is it just a trait of port forwarding that if you keep that port open to be forwarded to you ip, that even when you are not using that application, the router is still constantly trying to send you packets?

Do I then have to manually open and close that port every time I use and close the application? Or it does not effect anything that the router is sending me packets when I don't need it?

 

you're probably being port scanned by people looking for vulnerable systems.

if the application communicating over that port doesn't have any security exploits, you should be fine.

 

I just installed azureus and it requires a port to be forwarded, I choose a port in the range of 49152 to 65535. Do you think I should maybe choose another port instead? Maybe the port I chose was being scanned more often than the rest? I did noticed also that zonealarm blocked a lot of stuff when that port was opened. Port 57329 to be exact, but I am going to change it now and see.

 

does it seriously need that big of a range of ports? azureus is a bittorrent client, right?

 

No no, I think you might have misinterpreted, what I meant was, I chose 'One' port from that range, 49152 to 65535, which was 57329, to be opened for the torrent client. In short, only port 57329 was open to be forwarded to my static ip.
I was wondering if you guys know that maybe that port was being scanned more often than others? I already changed to another port with that range, haven't tested it yet.

I thought to myself for the reason of port scanning happening; might it because it was used as a torrent port and once I closed the application, other peers were still scanning my port to see if I was still there causing the testing packets being sent and received even when I closed down the torrent client.

Edit: so in short, it's a trait for a torrent port to behave like that and no matter what port I used, it will always be scanned when I closed the app. Therefore for security reason, I should manually enable and disable port forwarding when I do need to use the client!?

I guess I don't use it often enough to have the port opened constantly, but I do want to know the reason behind though. I was trying to DL linux to play with on my laptop.