DOCUMENT:Q233387 10-AUG-2001 [winnt] TITLE :RAS Clients Cannot Access LAN When IP Forwarding is Disabled PRODUCT :Microsoft Windows NT PROD/VER:winnt:4.0 OPER/SYS: KEYWORDS: ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server version 4.0 - Microsoft Windows NT Workstation version 4.0 ------------------------------------------------------------------------------- SUMMARY ======= When 'IP Forwarding' is disabled, Windows NT 4.0 no longer performs static routing based on the routes defined in its route table. As a result, in addition to not routing IP packets between its distinct local subnets, Windows NT 4.0 does not route IP packets from its RAS clients to its LAN, even if these RAS clients use IP addresses that belong to the same subnet as that of the LAN by design. MORE INFORMATION ================ 'IP Forwarding' can be enabled or disabled in Control Panel Network, Protocols tab, properties of TCP/IP, Routing tab. With 'IP Forwarding' enabled, Windows NT 4.0 routes IP packets according to the routes defined in its route table. This enables a Windows NT 4.0 RAS server to route IP traffic to and from a RAS client using the host route whose destination is the RAS client's specific IP address and whose gateway is the RAS server's NdisWAN Adapter. When IP forwarding is disabled, a Windows NT 4.0 RAS server no longer routes IP traffic according to its route table and so RAS clients, regardless of their IP address, are NOT able to send or receive IP traffic to or from the RAS server's LAN. In this respect, disabling 'IP Forwarding' restricts a RAS client's access to its RAS server, even if the RAS service's TCP/IP configuration is set to permit its RAS clients 'Access to Entire Network.' Additional query words: ====================================================================== Keywords : Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400 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.