Blocked incomming on PORT 139

Running Window XP SP3
AVG Version 8
Spyware terminator
COMODO
All up to date.

I just noticed that COMODO has been blocking incoming traffic on PORT139 it appears to be coming form all the other (4) machines on my network.
This seems to have started on the 20th August about the time I started to roll out AVG 8. Though this may be coincidental.

The AVG8 bit is coincidental.

Windows networking protocols are extremely chatty. Each machine will broadcast it’s network identification and services to all other machines on the LAN. That’s just how the protocols got defined way back when.

Probably the easiest solution, is to make sure the LAN broadcast address is listed in yor CFP network zone. The broadcast address is always the highest address in your address range. So if your LAN is 192.168.1.x, the broadcast address is 192.168.1.255.

To add that address into your CFP network zone, you need to edit the zone definition. Open CFP, click Firewall → Common Tasks, My Network Zones. You want to edit the zone for your LAN, and “add a new address”. That address is your LAN broadcast address.