Arrrggghh! System is trying to receive Internet connection nbname(137) - UDP

I would very much appreciate help with this pesky annoyance. If I am posting to a wrong forum OR if theris an answer lready tha I have not foun then PLEASE just direct me there. I cannot find a solution so far anywhere!

EVERY time I startup my system I get an alert that System is trying to receive an Internet connection nbname(137) from remote - UDP. All I want is to not have to click the Allow - OK button EVERY SINGLE TIME >:( I start up the system.

By experimentation I believe I found that messages / connection on ports 137, 138 and 139 come through my router from my Netgear PS110 print server. If I block or otherwise interfere with them, I lose the connectivity to the print server / printers attached to it.


  1. Is it SAFE to allow these connections
  2. Is there a way to set up the Firewall+ rules so that I do not have to click the Allow - OK button EVERY SINGLE TIME I START the system?

What I find interesting is that since I added “Remember my answer,” the rule alowing this connection is entered dozens of times into the Application firewall rules.

ONe more item: Disabling UDP over TCP also disables the print server.

System is Windows XP Pro SP3.

Help would be much appreciated!


nbname is used for netbios name resolution and is safe within your private network. Depending what is on your network, it is needed. is a private address and allowing the nbname is OK. As per setting a rule, you should be able to do so.

Go to the Firewall in the GUI, Advanced, Network Security Policy, Add a new rule. Do not choose an application, choose custom policy and choose add again. From there, you can setup pretty much any rule you wish to apply to your system.

Hope it helps


Alternatively, create a Zone that covers the IP addresses of the devices on your LAN and then use this Zone in your rules.

Ewen :slight_smile:

For my understanding:

When I cover the adress of my router, e.g., into the adress room for my ‘safe’ lan is there no risk? What I need to understand is, whether any connection allowed including my router adr. (Lan interior adr.) is safe or if there is a risk of slipping through the into the wild internet?

Nope. Addresses in the 192.168.X.X address range are classed as private and are non-routable across the internet. Any packet with this address would be chopped and dropped by the first router it encountered outside your LAN.

Hope this helps,
Ewen :slight_smile:


I have a Virtual Machine installed that has some virtual adapters in the 192.168.124.X, 192.168.168.X or so range. My Lan is 192.168.178.X .

Is there a way to add one rule for my lan embracing all these adr. ?
I tried to do so in my network zones by entering but that did not do the trick. I pressed afterwards then stealth ports…

You could set up a zone using netmasks, as opposed to specific addresses.

Start address :
Netmask :

This combination will apply to any address that begins with 192.168.

Hope this helps,
Ewen :slight_smile:

I have the same prob as original poster - a warning at every login that ‘system’ is trying to receive a connection from my local router ( on nbname(137).

I’ve allowed it many times but it still comes back. I don’t want to create a safe zone for my local network because my daughters laptop and some of her friends connect - and I have no control over what is on their machines.

Anyway the zone solution seems like a workaround - I’d like to know why the Comodo firewall doesn’t retain the instruction that this is an OK connection. Is this a bug in the firewall or some other underlying reason why every instance is treated as new, and worth telling me about?

Try telling it to block and remember the answer. Does that do the trick for you?