Re: UDP port 137

[davidg () genmagic com (David Gillett)]

On 27 Jan 99, at 17:34, Burgess, John (EDS) wrote:

> My firewall has been alerting me to "possible port scans" on UPD for
> port 137. This seems to occur from a number of source addresses and
> domains on the internet, some resolve-able, some not.  Does anyone
> know of a reason I should be concerned? 

  Port 137 is the NetBIOS name service port.

  It's *possible* that someone is trying to scan your network this way, 
but the far more likely case is that these are folks connecting Windows 
clients directly to the Internet with file/printer sharing enabled.  
Probably many of the ones you can't resolve are dial-ups.
  You *do* want this blocked at the firewall, but you shouldn't lose 
any sleep over it once you've done that.


David G