Authorizing DHCP and RIS servers in Windows 2000 Server

by Jim Boyce | May 07, 2007 7:00:00 AM

Tags: NETWORKING, Servers, security issue, Jim Boyce, DHCP, server, Microsoft Windows 2000, RIS Server, Microsoft Windows 2000 Server, Microsoft Windows, Windows 2000 Server Tips Newsletter

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Takeaway: When you're dealing with services such as DHCP, you never know who may be on the other end of the network. Here's what you need to know about authorizing access to your Windows 2000 Servers through Active Directory.

Networks are generally not safe enough. Just take TCP/IP, for example. It provides no real security, and anyone with access to the network can intercept and read all TCP/IP packets on the network. The same goes for other protocols and services.

The security issue is even more problematic with services like DHCP and RIS. Theoretically, every user with access to the network could install a DHCP server to give out illegal IP numbers. Nothing prevents a cracker from doing this.

Well, almost nothing, since all Windows 2000 DHCP and RIS servers have to be authorized before they can start providing their usual services. When an administrator authorizes a server, the server is added to a special authorized list in Active Directory. When these services start, authorization is verified. If they're not authorized, they'll stop and won't provide any services. This way, DCHP servers set up by just any user will not be able to provide IP numbers.

Both types of servers (DHCP and RIS) are authorized through the same DHCP console (Start | Programs | Administrative Tools | DHCP). When authorizing a server, right-click on DHCP in the console and then select the Manage Authorized Servers option. Click the Authorize button and then specify the name or IP address of the server you want to authorize.