Installing And Configuring DHCP With Windows Server 2012

Installing and configuring DHCP with Windows Server 2012 is thankfully pretty easy, and doesn’t take much longer than 15 minutes if you’re starting with a fresh network.  For this tutorial, you’ll learn how to configure basic DHCP services only – future tutorials will include more advanced DHCP configuration.  Keep reading to learn how to install and configure DHCP on Microsoft Server 2012.

First things first, you’re going to want to start with as fresh of a server as possible, but if you’re using a machine that’s already in production, that’s fine as well.  You also want to start this process with an end goal in mind, keeping in mind exactly what you are trying to accomplish with this DHCP installation.  Perhaps you want to consolidate as much network management as possible in one area, keep better track of your network addresses, or even configure some sort of high availability scenario.  One of the great things about Microsoft Server 2012 is that it makes all of these scenarios incredibly easy to accomplish, so let’s start with the first step – installing the bare-bones DHCP server.
Start off by opening up the Add Roles and Features area, and installing the DHCP services.
Click next through the wizard to install DHCP, and accept the defaults as shown below.  Proceed through the wizard, skipping the installation of additional features for now.

Add Roles For DHCP Server

After reading through the prompts carefully, go ahead and click Install.

Installing DHCP Server

Now click on the DHCP menu – you’ll notice that more configuration is required.  Microsoft Server 2012 is pretty good about showing you a “call to action” when it’s necessary with the yellow highlight bar.  Click on the “tasks” area to finish the post deployment configuration.

Post Deployment DHCP Configuration

This part works similar to the dcpromo tool, which has you first install the role, then start configuring options and option settings.  Because you may have multiple sites or separation of duties, the wizard will have you create special Security Groups for delegation purposes.  This is also handy for junior level admins to cut their teeth on, without having the ability to crater your network.  A poorly configured DHCP server has the ability to absolutely nuke a network, so it’s best to stop a moment at this point and think about exactly who will have the ability to make changes.
After pondering for a moment, use a sufficiently privileged account to authorize the DHCP server.

DHCP Post Install Wizard

Now commit the changes to create the appropriate Security Groups and authorized users, and restart either the service or the server when prompted.

Restart DHCP Service

Now you can launch the DHCP snap-in from the Administrator tools, and get to configuring your DHCP scope.  What’s a DHCP scope?  It’s simply a range of IP addresses that the DHCP server is authorized to manage.  Note : make sure to use a different scope outside of your normal subnet IF you already have an existing DHCP server in place.  Having two DHCP servers on the same scope is a no-no and can lead to a lot of headaches once they start fighting over leases.
Expand the scopes and configure your IPV4 scope first.  Right click on IPV4, and select New Scope.

New DHCP Scope

I like to use the first 10-20 IP addresses of the scope for devices that I know will need a static IP, but that I will not want to manage with DHCP reservations.  Firewalls and edge devices are a good example of devices that should just have static IPs, as opposed to being managed by the DHCP server.  I’m also going to go with a /20 allocation ( 4 24′s ) to give myself some breathing room on IP’s for the time being.

IP Address Range

Now set your exclusions as mentioned previously.  You can add IP addresses individually, or whole ranges at once depending on your needs.

Add DHCP Exclusions

The default lease time of 8 days is fine for most scenarios.  If you have a network that has a large amount of mobile devices, you may want to consider creating a separate scope with a lower lease time, or creating a scope with more IP addresses.

DHCP Lease Reservation

Next you get to configure your options for this particular DHCP scope.  DHCP scope options are simply an additional function of DHCP, which at its most basic form simply assigns IP addresses.  Without scope options, a DHCP server would basically be a glorified way of handing out APIPA addresses.  In other words, it would be useless ;)
Set your default gateway :

Set Default Gateway

Now your name servers :

DNS Servers

And finally, activate your scope.

Activate Your Scope

At this point your DHCP server is authorized to handle IP address requests to DHCP enabled clients on your network.
Congratulations on installing and configuring DHCP with Windows Server 2012!
In coming posts, I’ll be walking you guys through the process of configuring more advanced DHCP scope options, reservations, and other aspects of DHCP.

Posted in: Window Server