Checking IP address assignment
You can use ipconfig to check the currently assigned IP address and other configuration information. To obtain information for all network adapters on the computer, enter the command ipconfig /all at the command prompt. If the IP address has been assigned automatically, you’ll notice an entry for Autoconfiguration IP Address.
In the following example, the autoconfiguration IPv4 address is 169.254.98.59:
Windows IP Configuration
Host Name…: DELTA
Primary DNS Suffix…: microsoft.com Node Type…: Hybrid
IP Routing Enabled…: No
WINS Proxy Enabled…: No
DNS Suffix Search List…: microsoft.com Ethernet adapter Ethernet:
Connection-specific DNS Suffix…:
Description…: Intel Pro/1000 Network Connection Physical Address…: 23-15-C6-F8-FD-67
DHCP Enabled…: Yes
Autoconfiguration Enabled…: Yes Autoconfiguration IP Address: 169.254.98.59 Subnet Mask…: 255.255.0.0
Default Gateway…:
DNS Servers…:
Understanding scopes
Scopes are pools of IPv4 or IPv6 addresses you can assign to clients through leases. DHCP also provides a way to permanently assign a lease on an address. To do this, you need to create a reservation by specifying the IPv4 address to reserve and the media access control (MAC) address of the computer that will hold the IPv4 address. The reservation thereafter ensures that the client computer with the specified MAC address always gets the designated IPv4 address. With IPv6, you can specify that a lease is temporary or nontemporary. A nontemporary lease is similar to a reservation.
You create scopes to specify IP address ranges that are available for DHCP clients. For example, you could assign the IP address range 192.168.12.2 to 192.168.12.250 to a scope called Enterprise Primary. Scopes can use public or private IPv4 addresses on the following networks:
■ Class A networks IP addresses from 1.0.0.0 to 126.255.255.255
■ Class B networks IP addresses from 128.0.0.0 to 191.255.255.255
■ Class C networks IP addresses from 192.0.0.0 to 223.255.255.255
■ Class D networks IP addresses from 224.0.0.0 to 239.255.255.255
NOTE The IP address 127.0.0.1 is used for local loopback (and so are any other IP addresses in the 127.x.y.z address range).
Scopes can also use link-local unicast, global unicast, and multicast IPv6 addresses. Link-local unicast addresses begin with FE80. Multicast IPv6 addresses begin with FF00. Global (site-local) unicast addresses include all other addresses except:: (unspecified) and::1 (loopback) addresses.
A single DHCP server can manage multiple scopes. With IPv4 addresses, four types of scopes are available:
■ Normal scopes Used to assign IPv4 address pools for class A, B, and C networks.
■ Multicast scopes Used to assign IP address pools for IPv4 class D networks. Computers use multicast IP addresses as secondary IP addresses in addition to a standard IP address.
■ Superscopes Containers for other scopes that are used to simplify management of multiple scopes and also support DHCP clients on a single physical network where multiple logical IP networks are used.
■ Failover scopes Scopes split between two DHCP servers to increase fault tolerance, provide redundancy, and enable load balancing.
With IPv6, only normal scopes are available. Although you can create scopes on multiple network segments, you’ll usually want these segments to be in the same network class, such as all IP addresses that are class C.
TIP Don’t forget that you must configure DHCPv4 and DHCPv6 relays to relay DHCPv4 and DHCPv6 broadcast requests between network segments. You can configure relay agents with the Routing and Remote Access Service (RRAS) and the DhCP Relay Agent Service. You can also configure some routers as relay agents. These services can be installed as part of the Remote Access role. On a server with no other policy and access role services configured, you can install the Remote Access role by using the Add Roles And Features Wizard.
Installing a DHCP server
Dynamic IP addressing is available only if a DHCP server is installed on the network. By using the Add Roles And Features Wizard, you install the DHCP server as a role service, configure its initial settings, and authorize the server in Active Directory Domain Services (AD DS). Only authorized DHCP servers can provide dynamic IP addresses to clients.
Installing DHCP components
On a server running Windows Server 2012 R2, follow these steps to enable the server to function as a DHCP server:
1. DHCP servers should be assigned a static IPv4 and IPv6 address on each subnet to which they are connected and will service. Be sure that the server has static IPv4 and IPv6 addresses.
2. In Server Manager, tap or click Manage, and then tap or click Add Roles And Features, or select Add Roles And Features in the Quick Start pane. This starts the Add Roles And Features Wizard. If the wizard displays the Before You Begin page, read the Welcome text, and then tap or click Next.
3. On the Installation Type page, Role-Based Or Feature-Based Installation is selected by default. Tap or click Next.
4. On the Server Selection page, you can choose to install roles and features on running servers or virtual hard disks. Either select a server from the server pool or select a server from the server pool on which to mount a virtual hard disk (VHD). If you are adding roles and features to a VHD, tap or click Browse, and then use the Browse For Virtual Hard Disks dialog box to locate the VHD. When you are ready to continue, tap or click Next.
NOTE Only servers running Windows Server 2012 R2 and that have been added for management in Server Manager are listed.
5. On the Select Roles page, select DHCP Server. If additional features are required to install a role, you’ll get an additional dialog box. Tap or click Add Features to close the dialog box and add the required features to the server installation. When you are ready to continue, tap or click Next three times.
6. If the server on which you want to install the DHCP Server role doesn’t have all the required binary source files, the server gets the files via Windows Update by default or from a location specified in Group Policy.
NOTE You also can specify an alternate path for the required source files. To do this, click the Specify An Alternate Source Path link, enter that alternate path in the box provided, and then tap or click OK. For network shares, enter the UNC path to the share, such as \\CorpServer82\WinServer2012\. For mounted Windows images, enter the Windows Imaging (WIM) path prefixed with WIM: and including the index of the image to use, such as WIM: \\CorpServer82\WinServer2012\install.wim:4.
7. After you review the installation options and save them as necessary, tap or click Install to begin the installation process. The Installation Progress page tracks the progress of the installation. If you close the wizard, tap or click the Notifications icon in Server Manager, and then tap or click the link provided to reopen the wizard.