If you use TCP/IP as the only protocol, file sharings with NetBIOS use
port numbers 137 through 138. You have to allow traffic incoming AND
outgoing because the server establishes a reciprocal connection back to
the client. The same setup applies to all SMB connection like Samba of
A good place to look for answers to questions like this is the RFC
On Tue, 29 Apr 97 14:53:04 CST
"Dick Mosher" <dick_mosher @
| We are trying to set up NT file sharing across an internal firewall,
| and can find very little documentation on its mechanics. Can anyone
| tell me what port(s) it uses? Thanks.
| dick_mosher @
Hope this helps!
(Senior Security Consultant)
Sauer, Küster und Partner GmbH
Dietrich-Bonhoeffer-Straße 1-3, 35037 Marburg, Germany
fon: +49 6421 938300, fax: +49 6421 938390, URL: www.skp.de