Application of routers and DHCP

In some enterprises, we can perform some configurations to efficiently complete the work. Then we can achieve this by using routers and DHCP. Due to work requirements, the LAN managed by the author often changes the gateway server and DNS server. Each time, you have to manually modify the client's gateway address and DNS server address. This requires a lot of work. Can't I concentrate all the network configuration information of the client on one server for dynamic configuration? I found that the DHCP server also integrates functions such as gateway configuration and DNS Server Resolution. at ordinary times, we only pay attention to the Dynamic Address Allocation Function of the DHCP server, ignoring other features it has.

1. configuration on the DHCP server

To implement the gateway configuration and DNS Server Resolution functions, we have to make some settings on the DHCP server first. This article takes Windows Server 2003 as an example.

Step 1: Create a scope

Choose Start> program> Administrative Tools> DHCP to open the DHCP manager. Create a new scope on the DHCP server. In the "DHCP manager" window, right-click the DHCP server option and choose "New Scope" from the shortcut menu.

In the new scope wizard dialog box, click "Next", specify the name and description of the scope in the "Domain Name" dialog box, and then click "Next, then assign the IP address range for this scope. For example, if I want to restrict the IP address range to "192.168.0.5 ~ 192.168.0.123.

Next, define the subnet mask, set the value in the "length" column to "24", and click "Next, in the "add exclusion" dialog box, specify the IP address range to be excluded from the scope. If not, click "Next. Finally, configure the "Lease Term". In the "Configure DHCP options" dialog box, select "yes, I want to configure these options now" and click "Next, you can specify the configuration information of the default gateway and DNS server.

Step 2: configure the Default Gateway

In the "router (Default Gateway)" dialog box, add the gateway IP address used by the client. In the "ip address" column, enter the default gateway IP address, click "add", add the address to the gateway address list box, and click "Next.

Step 3: configure the DNS server

In the "Domain Name and DNS server" dialog box, configure the DNS server information. In the "server name" column, enter the machine name of the DNS server, enter the IP address of the DNS server in the "ip address" column, and click "add" to add the server. After clicking the "Next" button, you can also configure the "WINS server". If no WINS server is configured in the network, click the "Next" button.

Finally, select "yes, I want to activate this scope now" and click "finish" to complete the configuration of the DHCP server, the DHCP server is bound with the default gateway and DNS resolution functions.

Step 4: configure the client

The client configuration is very simple. You only need to set the "TCP/IP protocol" attribute of the network adapter connecting to the LAN to "automatically obtain the IP address, you do not need to manually set the default gateway and DNS server options. The network configuration information of all clients is provided by the DHCP server.

2. Modify the default gateway and DNS Server

Since the default gateway and DNS server can be configured on the DHCP server, it is very easy to modify the default gateway and DNS server information used by the client.

In the DHCP manager window, expand the newly created scope and select "scope options". In the window on the right, you can see the "vro" and "DNS server" options.

Double-click the "vro" option to bring up the "scope options" dialog box. In the default gateway list box, select the original gateway IP address and click "delete, enter the new gateway IP address in the "ip address" column, click "add", and then click "OK" to modify the default gateway IP address. The DNS server and default gateway are modified in the same way.