Use of DHCP relay

The network is always complex, so we can use DHCP servers to manage IP addresses well. Some DHCP relay functions are also involved. Here we will take a look at the Advanced content about DHCP relay. Use a DHCP server (PC version) across subnets ). To improve network security, a larger LAN is usually divided into multiple subnets. However, the DHCP server can only provide services for the machines in this subnet. configuring the DHCP server for each subnet will result in waste. How can I enable a DHCP server to provide TCP/IP configuration services for multiple subnets at the same time?

Taking the two subnets A and B managed as an example, subnet A is configured with a dhcp server, and subnet B does not have a dhcp server. The following configuration operations are performed on subnet B:

1. Configure routes

In subnet B, select A Windows 2003 Server and configure it as A router to connect two subnets, A and B (the server belongs to both subnets at the same time ). Go to "Control Panel> Management Tools", run the "Routing and Remote Access" tool, right-click the local server, and select "configure and enable Routing and Remote Access". The installation wizard dialog box is displayed, select "custom configuration", click "Next", select "LAN routing", and click "finish ".

2. configure a relay proxy

In the Routing and Remote Access Windows, expand "Local Server> IP Route Selection> General", right-click "General", and select "add route protocol ", select "DHCP relay agent" in the new routing protocol window and click "OK.

Right-click the DHCP relay agent and select "properties". The "DHCP relay agent properties" dialog box is displayed, on the "General" tab, enter the IP address of the DHCP server of subnet A in the "server address" column, click "add", and then click "OK.

Right-click the DHCP relay agent and select "New Interface". The dialog box for the new interface of the DHCP relay agent is displayed. In the "interface" box, select the interface that can access subnet, that is, to connect to the NIC of subnet A, click "OK. In the displayed "DHCP relay properties" dialog box, make sure that the "relay DHCP packet" is selected, its relay function is enabled, and then click "OK. After completing the preceding configuration, the client of subnet B can use the DHCP server of subnet.

Tip: the relay proxy is a small program that transfers DHCP/BOOTP messages between DHCP clients and DHCP servers in different subnets. Next we will configure this Windows 2003 Server as a DHCP relay proxy server. In this way, when A client of subnet B sends A request, the relay proxy forwards the request to the DHCP server of subnet, then, the TCP/IP configuration information returned by the DHCP server is forwarded to the client of subnet B.