On Wed, 28 Aug 96 09:03:57 edt arager @
mcgraw-hill .
com wrote:
> I have the same question....which has not been answered.... I
> normally see netbios traffic on UDP/137, UDP/138, and TCP/139. Under
> what conditions does NT/95/WFW use TCP/137,TCP/138, or UDP/139 for
> netbios communications??? [there seems to be entries for both in most
> newer /etc/services tables]. I would love to know how to get netbios
> to be TCP only..........
>
It's a configurable option whether to use the TCP/IP transport stack,
NetBEUI (and maybee even ISO). NetBIOS over TCP/IP is defined in
RFC1001 & RFC1002.
IF a site decides on using TCP/IP for the NetBIOS traffic, then the
mentioned ports will be used. The typical use is for file and printer
sharing using a NT Advanced Server or a Unix paltform as server(s).
The NetBIOS protocol/interface defines its own naming service which is
implemented on port 137. The most commen implementations are B-node
implementations where all naming request are broadcasted (UDP). P-node
implementations (aka Domain Name System) are becomming increasingly
popular and in this case it might be possible to avoid UDP traffic?
Avoiding UDP traffic for a B-Node implementation would lame the naming
protocol but may be possible using quite extensive naming
configurations (a là /etc/hosts files).
Typically you don't want in- or outgoing NetBIOS related traffic
through your firewall.
Hope this helps!
/Frederik
|
|
