How can clients enjoy Dynamic Allocation of DHCP servers for a long time?

We can use DHCP servers to manage a large network and a wide range of IP addresses. For example, the following is an example. In my company, the local area network of the sales department is growing and the number of clients increases sharply. donggua, a network manager of the sales department, wants to use the DHCP server to dynamically allocate IP addresses to avoid the trouble of manually assigning IP addresses to clients. In this way, the IP address of the client changes frequently, which makes daily maintenance difficult.

How can we enable the client to obtain the IP addresses allocated by the DHCP server and have these dynamically assigned IP addresses for a long time? Donggua found the "celebrity" jelly in the LAN field and asked him to help solve this problem.

Intelligent jelly can solve this problem by setting the "Lease Term" parameter of the DHCP server. How is it implemented? Winter melon is still confused. Take the DHCP Server of Windows Server 2003 as an example to explain the specific implementation process.

Install DHCP Service

Because the DHCP service is not installed in Windows Server 2003 (Windows 2003) by default, the DHCP service must be installed first for jelly.

On the Windows 2003 Server, click Start> Settings> Control Panel to run add or delete programs. In the displayed window, switch to the Add/delete Windows Components page. In the "Windows component wizard" dialog box, select the "Network Service" option and click the "details" button below.

In the displayed "Network Service" dialog box, select the "Dynamic Host Configuration Protocol (DHCP)" option (figure 1) and click "OK. In the "Windows component wizard" dialog box, click "Next" to start configuring and installing the DHCP service, and then click "finish.

Figure 1

The full name of the jelly prompt DHCP is Dynamic Host Configuration Protocol (Dynamic Host Configuration Protocol). The built-in DHCP server in Windows can provide IP Configuration information for clients in the network, such as the IP address, subnet mask, default gateway address, WINS server address, and DNS server address. This saves the trouble of manual configuration by the network management for clients.

Create Scope

After installing the DHCP service on a Windows 2003 Server, Jelly needs to create a new scope to assign IP addresses to clients in a CIDR block.

In the "DHCP manager" window, right-click the DHCP server option and choose "New Scope" from the shortcut menu (figure 2 ).

Figure 2

In the pop-up "create scope wizard" dialog box, click "Next" and specify the name "CPCW" and description of the scope in the "Domain Name" dialog box, click "Next.

Set the IP address range for this scope. For example, set the IP address range to "192.168.0.10 ~ 192.168.0.188. Enter "192.168.0.10" in the "Start IP Address" column, enter "192.168.0.188" in the "end IP Address" column, and then 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 you want to exclude in the scope. If not, click "Next. Then configure the "Lease Term". Here, the term value cannot be set to "unlimited", so the default value "8 days" is used temporarily (Figure 3 ). In the "Configure DHCP options" dialog box, select "Yes. I want to configure these options now". Click "Next" to configure the default gateway and DNS server, click "finish.

Figure 3

Jelly prompts that because in the new scope wizard, jelly can only adjust the time of the "Lease Term" parameter value and cannot be set to "unlimited" status, therefore, the default value is "8 days ".

Next, we need to modify the term of the lease and change the value to "unlimited" to fix the dynamic IP address.

Modify Lease Term

Although jelly has created a new scope named "CPCW" on the DHCP server, it is responsible for dynamically allocating "192.168.0.10 ~" to the client ~ The IP address of 192.168.0.188, but the IP address lease term is still the default value, only 8 days, so the IP address of the client may change every 8 days.

Now, you only need to change the IP address lease term to "unlimited. Although the IP address is dynamically allocated when the client applies for it for the first time, the IP address will remain unchanged.

In the DHCP server console window, right-click "CPCW" and choose "properties" from the context menu to switch to the "General" tab (figure 4 ), select the "unlimited" option in the "Lease Term of the DHCP client" box, and click "OK. In this way, the dynamic IP addresses applied by clients within the "CPCW" scope will remain unchanged, and the troubles of donggua will also be solved.

Figure 4

The jelly prompt "Lease Term" refers to the time period for the IP Address Configuration Information allocated to the client by the DHCP server. The default value is 8 days. That is to say, the IP address configuration information obtained by the client can only be used for 8 days. Once the validity period is reached, you must apply for IP Address Configuration Information from the DHCP server again, so the IP address of the client will change, this makes it more difficult for the network administrator to manage the client.