Microsoft KB Archive/177335

= How to Create a Demand Dial PPTP Interface =

Article ID: 177335

Article Last Modified on 11/1/2006

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APPLIES TO


 * Microsoft Windows NT Server 4.0 Standard Edition
 * Microsoft Routing and Remote Access Service Update for Windows NT Server 4.0
 * Microsoft BackOffice Small Business Server 4.0
 * Microsoft BackOffice Small Business Server 4.0a
 * Microsoft BackOffice Small Business Server 4.5
 * Microsoft BackOffice Server 4.5

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This article was previously published under Q177335



SUMMARY
With a Microsoft Windows NT Server computer that is using the Microsoft Routing and Remote Access Service (RRAS) Update, you may want to create a Point-to-Point Tunneling Protocol (PPTP) interface that automatically connects to a PPTP server when a resource is requested. This article discusses the steps needed to create a demand dial PPTP interface.



MORE INFORMATION
To configure a demand dial PPTP connection, use the following steps:

NOTE: The following procedure assumes that you have successfully installed RRAS and PPTP.

 From Routing and RAS Admin, right-click LAN and Demand Dial Interfaces and then click Add Interface. Use the Demand Dial Wizard to create a Demand Dial interface for a Point-to-Point (PPP) connection using a modem or ISDN RAS device and appropriate phone number.

NOTE: In a branch office that uses the Internet, the phone number would be the phone number of the local Internet Service Provider (ISP). Repeat steps 1 and 2, but use a Virtual Private Network (VPN) RAS device and the IP address of the PPTP server.

NOTE: In a branch office that uses the Internet, the IP address would be the IP address of the PPTP server's Internet interface. From Routing and RAS Admin, expand the IP Routing folder, right-click Static Routes, and then click Add Static Route.  Create a static host route to the PPTP server's PPP interface. An example is shown below where the IP address of the PPTP Server is 192.100.100.1:

     Destination : 192.100.100.1 Network Mask: 255.255.255.255 Gateway    : 1.1.1.1 Metric     : 1 Interface  : PPP Connection to the ISP   Create a static route (or routes) for the IP network IDs of the corporate intranet that will be accessed through the PPTP tunnel. An example is shown below where the corporate intranet network ID is 10.0.0.0:

<pre class="fixed_text">     Destination : 10.0.0.0 Network Mask: 255.0.0.0 Gateway    : 1.1.1.1 Metric     : 1 Interface  : PPTP Connection to the Corporate network </li></ol>

The PPTP tunnel is automatically bought up through the following process (using the example information above):


 * 1) Packets destined for the network ID 10.0.0.0 are forwarded using the corporate intranet static route to the "PPTP Connection to the Corporate network" interface object.
 * 2) The PPTP Connection to the Corporate network interface object must establish a PPTP tunnel with the PPTP Server at its configured IP address of 192.100.100.1.
 * 3) To establish a tunnel, a TCP connection must be established.
 * 4) TCP connection packets to the address of 192.100.100.1 are forwarded to the "PPP Connection to ISP" interface object using the host route for the corporate PPTP Server.
 * 5) The "PPP Connection to ISP" interface is connected.
 * 6) The PPTP tunnel is connected over the PPP connection.
 * 7) Packets sent to the corporate intranet are sent over the PPTP tunnel.

For additional information about configuring Routing and Remote Access Service on Small Business Server, please see the following article in the Microsoft Knowledge Base:

ARTICLE-ID: 192614

TITLE : Routing and Remote Access Service on Small Business Server

Additional query words: dod dial on demand

Keywords: kbhowto kbnetwork KB177335

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