How to Configure a Firewall for Windows NT and Trusts

Last reviewed: February 9, 1998
Article ID: Q179442

The information in this article applies to:

Microsoft Windows NT Server versions 4.0

SUMMARY

To establish a domain trust relationship across a firewall, the following ports must be enabled:

   PORT 135 (TCP or UDP) for Remote Procedure Call(RPC)Service
   PORT 137 (UDP) for NetBIOS Name Service
   PORT 138 (UDP) for NetBIOS datagram (Browsing)
   PORT 139 (TCP) for NetBIOS session (NET USE)
   ALL PORTS above 1024 for RPC Communication

Name Resolution can be provided through an LMHOSTS file. For additional information on browsing with LMHOSTS, please see the following article in the Microsoft Knowledge Base:

   ARTICLE-ID: Q150800
   TITLE     : Domain Browsing with TCP/IP and LMHOSTS Files

Alternatively, a trust can be established through point-to-point tunneling protocol (PPTP). For PPTP, the following ports must be enabled:

   PORT (TCP) 1723 for PPTP
   IP PROTOCOL 47 (GRE)

MORE INFORMATION

In addition, administration applications (such as DHCP Manager and WINS Manager) typically use randomly assigned RPC ports.

Additional query words: tcpip
Keywords : ntdomain NTSrv
Version : WinNT:4.0
Platform : winnt
Hardware : x86
Issue type : kbinfo

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Last reviewed: February 9, 1998
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