Module 5: DHCP

Back in Module 2 you turned off VirtualBox’s built-in DHCP. In this module, DC01 takes over that job using the DHCP Server role. Windows Server is one common way organizations provide DHCP, although routers and other network appliances can provide it too. When you build CLIENT01 in Module 6, it will get its address automatically from DC01.

In This Module

• Install the DHCP Server role
• Authorize the DHCP server in Active Directory
• Create a scope for the lab network
• Configure the scope to point clients at your DC for DNS

What DHCP Does

DHCP hands out IP addresses so you do not have to configure every machine by hand. When a computer joins the network, it asks for an address, and the DHCP server replies with an address plus the other settings the machine needs: subnet mask, gateway, and which DNS server to use. That last setting is especially important in this lab. Clients must use DC01 for DNS so they can find the domain and its services.

Install the DHCP Server Role

1. On DC01, open Server Manager and click Manage > Add Roles and Features.
2. Click Next through to the Server Roles screen, check DHCP Server, and click Add Features when prompted.
3. Click Next through the rest and click Install.

Authorize the DHCP Server

In an Active Directory domain, Windows DHCP servers must be added to the list of authorized servers before they can issue leases. DC01 needs to be added to that list.

1. In Server Manager, click the yellow warning flag and choose Complete DHCP configuration.
2. Click Next, leave the default credentials because you are signed in as the domain Administrator, and click Commit.
3. Click Close when it finishes.

Create a Scope

A scope is the pool of addresses the server is allowed to hand out, plus the settings that come with them.

1. Open Server Manager > Tools > DHCP.
2. Expand dc01.lab.internal, right-click IPv4, and choose New Scope. A wizard opens.
3. Name: Lab Network. Description can stay empty.
4. IP Address Range:
   • Start: 10.0.10.100
   • End: 10.0.10.200
   • Length: 24 (the subnet mask fills in as 255.255.255.0)
5. Exclusions: leave empty and click Next. The pool starts at .100, so it already excludes DC01 at 10.0.10.10 and the VirtualBox gateway at 10.0.10.1. Keeping this lab’s planned static addresses outside the DHCP pool reduces the risk of duplicate addresses.
6. Lease Duration: keep the default (8 days) and click Next.
7. Choose Yes, I want to configure these options now and click Next.
8. Router (Default Gateway): enter 10.0.10.1, click Add, then Next.
9. Domain Name and DNS Servers: the parent domain should already say lab.internal, and 10.0.10.10 should already be listed as a DNS server. If not, enter them. Click Next.
10. WINS Servers: leave empty and click Next. WINS is a legacy name-resolution service that this lab does not use.
11. Choose Yes, I want to activate this scope now, click Next, then Finish.

The scope is now live. In the DHCP console, IPv4 should show a green check mark. Expand the new scope and select Scope Options. Confirm these three entries:

• 003 Router: 10.0.10.1
• 006 DNS Servers: 10.0.10.10
• 015 DNS Domain Name: lab.internal

The scope’s Address Leases folder will remain empty until Module 6, when CLIENT01 requests its first address.

Note

There is nothing on the network to hand addresses to yet, so a real test has to wait for CLIENT01. That is the very first thing Module 6 confirms.

Further Learning

These optional references provide additional detail from Microsoft and the RFC Editor:

• DHCP Server Overview explains leases, options, reservations, authorization, DNS integration, and other Windows DHCP features.
• Install and Configure DHCP Server provides Microsoft’s current graphical and PowerShell procedures for Windows Server 2025.
• DHCP Scopes explains address pools, exclusions, lease duration, reservations, and scope planning.
• RFC 2131: Dynamic Host Configuration Protocol defines how DHCP clients and servers exchange address information.

Checklist Before Moving On

• DHCP console shows IPv4 with a green check mark
• Scope Lab Network exists, range 10.0.10.100 to 10.0.10.200, and is active
• Scope options show router 10.0.10.1, DNS server 10.0.10.10, and DNS domain lab.internal

Continue to Module 6 to build CLIENT01 and join it to the domain.