Dial-up Remote Access Example
Updated: April 30, 2010
Applies To: Windows Server 2008, Windows Server 2008 R2
This scenario describes the configuration of a network for a branch office that is connected through a dial-up link.
A typical branch office network has the following characteristics:
One LAN segment.
Two-way, demand-dial connections to and from the corporate office.
The following illustration shows an example of a dial-up branch office network.
In this scenario, the server running Routing and Remote Access must be configured with a network adapter connected to the network for the branch office (for example, Ethernet) and an ISDN device or analog modem for connection to the corporate office.
Planning addresses for the branch office network
For IP addressing, the branch office network segment is assigned a network range of 254 addresses to allow for potential growth. In this scenario, the branch office network (Network F in the previous diagram) uses the address of 172.16.128.0 with a subnet mask of 255.255.255.0.
Routing protocols for the branch office network
For this branch office scenario, static routes are used for IP routing.
It is not necessary to use IP routing protocols to propagate IP routing information to the branch office. Instead, static routes are configured on the server running Routing and Remote Access. For an example of adding a static route, see Configuring the branch office network in this guide.
If there are many static routes or static services to add, RIP can be configured to use auto-static updates. Auto-static updates enable the router to automatically send a request for a list of routes from other routers. The list is then converted to static routes. For more information, see Perform Manual Auto-static Updates in the RRAS Deployment Guide.
Other services for the branch office network
Using a long-distance analog phone line or an ISDN line unnecessarily can be expensive. To prevent the initiation of a demand-dial connection except when information resources such as a Web site or file shares are accessed, DHCP and name servers are installed on the branch office network.
In this scenario, the DHCP service is used for automatic configuration of IP addresses and other information on client computers. Installing and configuring the DHCP Relay Agent on Router 6 might cause Router 6 to dial the corporate hub router every time a DHCP packet is sent by a computer in the branch office network. Therefore, a DHCP server is installed on the branch office network F.
DNS name servers are installed on the branch office network to enable local name resolution. The branch office name servers must be configured to replicate with the corporate name servers.