unknown port forwarding on T1200H

[SC]

Recently I upgrade the modem/router to Actiontec T1200H, and noticed that I have inbound port 4nnnn,or 5nnnnn, or 6nnnnn forwarded to my Windows PC.  If I deleted the port forwarding, it will come back immediately. Norton says I have no virus, but this port forwarding worries me.  Is it a virus? Why is it there?

[Nighthawk]

It's called UPnP (Universal Plug n' Play). The ports are opened automatically by applications you have running on your PC, including Windows itself. They are not unusual or dangerous in the vast majority of cases. If you have up to date software and antivirus, you'll be fine.

[SC]

I have up to date software and antivirus. It seems strange that I have three PC on the network, one Windows 7 starter, Windows 8.1 and a MacBook, but the ports are only forwarded to the Windows 8.1 machine. As well, the T1200H syslog showed lots of Upnp error 714 and 718s.

[Nighthawk]

All computers will have ports open for certain things. Not all programs use UPnP so not all connections will show up in that list. I wouldn't worry about it.

[SC]

Thanks Nighthawk.