Demand-Dial Routing with Windows

While the use of Windows 2000 as a traditional LAN or WAN router is debatable (based on the speed and popularity of hardware-based solutions), for smaller or branch offices the use of Windows 2000 as a demand-dial router can be both cost-effective and deliver decent performance. To configure Windows 2000 as a demand-dial router, you will of course need at least one dial interface, such as a modem or ISDN adapter.

When creating demand-dial connections, you have the ability to make them either one-way or two-way. In a one-way setup, only one system is allowed to dial the other. In a two-way setup, either system can initiate the connection. Before you can create a new demand dial interface, you must first ensure that the server is configured to allow demand-dial routing (configured in the properties of the server).

Right clicking on Routing Interfaces in Routing and Remote Access gives you the ability to create new demand-dial interfaces, which are configured via a wizard. Note that the naming of the connection is extremely important, since the user account that must later be created must match the name of the connection.

After choosing the device that you will use to connect, providing the phone number to be dialed and so forth, you will be presented with the screen below, which allows you to control which protocols will be routed, automate the creation of a user account, and so forth.

The next screen allows you to configure dial-out account properties for the connection. These will be used by the router when it initiates a connection, and an account much be configured on the receiving computer in order for this to function correctly. Don’t forget that the user account that you create on each remote router must match exactly the name of the demand-dial connection. Note also that the account you create must have permission to dial-in, and is susceptible to any remote access policies that you might have created.

A few remaining things that you should be aware of when using demand-dial routing:

  • Demand dial filtering (by port number) allows you to control which types of traffic will initiate the connection. For example, you might only allow HTTP traffic to initiate dial-up, while ignoring other traffic.
  • A demand-dial router should be configured with static routes, using a routing protocol (such as RIP) would cause the connection to be repeatedly initiated because of routing table updates. Another option, called auto-static mode, allows you to configure the router such that static routes are automatically added to the routing table at pre-defined intervals.
  • Note that you can also add static routes to the routing table upon connection by adding a static route to the dial-in properties of the user account that will be used for the connection.
  • To troubleshoot demand-dial connections, use the Rasmon.exe utility.

Author: Dan DiNicolo

Dan DiNicolo is a freelance author, consultant, trainer, and the managing editor of He is the author of the CCNA Study Guide found on this site, as well as many books including the PC Magazine titles Windows XP Security Solutions and Windows Vista Security Solutions. Click here to contact Dan.