DOCUMENT:Q241812 08-AUG-2001 [winnt] TITLE :DUN Clients Cannot Obtain Access to the LAN PRODUCT :Microsoft Windows NT PROD/VER:winnt:4.0 OPER/SYS: KEYWORDS:kbnetwork ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server version 4.0 - Microsoft Routing and Remote Access Service Update for Windows NT Server version 4.0 ------------------------------------------------------------------------------- SUMMARY ======= When you install Microsoft Proxy 2.0 on your Microsoft Windows NT 4.0-based computer, the common recommendation is to disable Internet Protocol (IP) forwarding. This is usually recommended to prevent the computer from routing packets to the internal network. This article describes the behavior of remote access Dial-Up Networking (DUN) clients based on whether this setting is enabled or disabled. MORE INFORMATION ================ When your Windows NT 4.0-based computer is running Remote Access Service (RAS) or Routing and Remote Access Service (RRAS) in addition to Microsoft Proxy 2.0, the IP forwarding setting controls the following behavior for remote access DUN clients: IP Forwarding Is Disabled ------------------------- Remote access DUN clients are able to obtain access to the Proxy 2.0 RAS (or RRAS) Proxy 2.0 server only. IP Forwarding Is Enabled ------------------------ Remote access DUN clients are able to obtain access to the Proxy 2.0 RAS (or RRAS) Proxy 2.0 server, and to resources on the local area network (beyond the proxy). NOTE: Proxy 2.0 Autodial is not affected by the IP forwarding setting, because the DUN connections are outgoing. To configure IP forwarding on your Windows NT 4.0-based computer: 1. Click Start, point to Settings, click Control Panel, and then double-click Network. 2. Click the Protocols tab, and then double-click TCP/IP Protocol. 3. Click the Routing tab, and then click to select or click to clear the Enable IP Forwarding check box. Additional query words: ====================================================================== Keywords : kbnetwork Technology : kbWinNTsearch kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbAudDeveloper kbRRASNTSearch kbRRASNT400 Version : winnt:4.0 Issue type : kbinfo ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.