TCP connection from port 139.nbsess

Comodo Internet Security - CIS Firewall Help - CIS
#1

I got an alert that my computer 192.168.1.1 wanted to receive a connection from the internet system 192.168.1.3 - TCP port nbsess 139. Source port 49319.

Why does it say from internet when it is from a computer on my own network?

I understand that relates to file sharing. I don’t think i have enable file sharing as the other pc has has a new instal of win 7 recently. i do have a network printer though. But have not printed to it from that source computer

#2

Probably because it hasn’t been designed to differentiate between Internet and non-Internet connections.

I understand that relates to file sharing. I don't think i have enable file sharing as the other pc has has a new instal of win 7 recently. i do have a network printer though. But have not printed to it from that source computer

The NetBIOS Session Service (NBSS) is one of three NetBIOS protocols used for file and printer sharing, the others being NetBIOS Name Service and NetBIOS Datagram Service. On Windows based operating systems, file and printer sharing is enabled by default. There are various ways of dealing with this kind of communication, it really depends on what you need.

#3

Thanks. Why would i suddenly get an alert when the pc it came from was unattended.

Also the GRC probe always says file sharing is not enabled in my pc. Any idea why?

#4

If you went to www.grc.com and ran shields up and it says there is no file sharing on your pc.
This would mean that your pc is not EXPOSING it’s file sharing to the internet which is what you want.
Also since you are saying your pc’s are using a 192.168 address this would indicate you are behind a NAT router with a firewall.

#5

Oh i see is sharing but not exposing. Out of curiosity if i wanted to expose the file sharing what would i turn on. i don’t

Also since you are saying your pc's are using a 192.168 address this would indicate you are behind a NAT router with a firewall.
yes I am

Thank you

#6

If you have a router then most likely it has firewall features so you’d have to open the ports for the file sharing service and then you’d have to do the same with your firewall on your computer I’d imagine.

#7

What applications are running on the PC from which the alert originated? Also, what were you doing at the time?

Also the GRC probe always says file sharing is not enabled in my pc. Any idea why?

From your IP address(s) you appear to be behind some sort of NAT device (a router?) if so, any port test like shields-up, will be looking at that device, not the PCs behind it.