Over the past week or so, my home network has had an increase of attempted access on different ports. The source IP has been different each time, but stuck to 3 TCP/IP ports. The destination address was different each time, but the port was the same. Anyone have any ideas on what could be causing this. All the attempts were stoped by Norton Internet Security. My home network is setup like the following:

1 Windows 2000 Server, Configured as Domain Controler, DHCP, DNS
4 desktop & 2 laptops, all running Windows XP Pro. Desktops are on a wired network and the laptops are connected through a Linksys 802.11b Access point with 64 bit WEP enabled
1 Netgear Security router, connected to a switch on the internal side and a cable modem on the WAN side

All computers have Norton Internet Security running, with the most recent updates installed. Windows on all machines are up to date, including recommended updates and drivers.

The ports that were used follows:

Source -> Destination
2454 -> 11085
4556 -> 11085
2140 -> 11085

Like I said above, both the source and destination IP's were different each time.

If you need more information, let me know. Thanks.