Server 2012 R2 DHCP

Posted on 2016-08-30
Last Modified: 2016-09-01
I have a physical server running 2012 R2 (replacing an older server running Server 2003), and I'm trying to use one of the NICs for a Ghost network. The old server runs to an unmanaged switch, and we connect PCs to this network to PXE boot into Ghost. However, we cannot get DHCP to run when connecting the new server to the network, and cannot even ping back and forth. We are disconnecting the cable from the old server and are using a different port on the switch, but we can't get this NIC to communicate with any other machines on the network, much less obtain an IP address. Is there something simple we're missing, i.e. firewall issue, NIC configuration, DHCP configuration, etc?
Question by:maximjon
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 3
LVL 21

Expert Comment

ID: 41777116
What happens if you configure the NIC statically?  Are you able to ping other devices?  That will help you decide if it is a DHCP issue or not.

It sounds as if there is a problem with the NIC, the cable, or the port on the switch.  Do either of the lights on the NIC light up when you connect the cable?  What about the lights on the port on the switch?

Author Comment

ID: 41777972
We've actually been able to ping back and forth from a client with a static IP once we tweaked the firewall. The NIC looks okay, and the ports on the client and switch all light up as they should. At this point it definitely looks like a DHCP issue.
LVL 21

Expert Comment

ID: 41778359
What is doing DHCP?  Can the server in question ping the DHCP server when using a static IP?  If you would post the results of ipconfig /all from the server in question when configured for a dynamic IP address it would be helpful.
Visualize your virtual and backup environments

Create well-organized and polished visualizations of your virtual and backup environments when planning VMware vSphere, Microsoft Hyper-V or Veeam deployments. It helps you to gain better visibility and valuable business insights.


Author Comment

ID: 41778514
It's a server with Windows Server 2012 R2, with a static IP address running DHCP. Everything looks like it's configured correctly, but we're not sure where to double-check. We're trying to get it to hand out a DHCP address to a client running Windows 7 at this point. There's an unmanaged switch in between, and the server will eventually be used to push Ghost images. We have an older server running Server 2008, which has been able to distribute addresses without any issues. We don't have them on the (very limited) network at the same time, and there are no other devices connected.

If we set a static IP address for the client, it and the server can ping each other. However, when we set the client to DHCP, it gives an APIPA IP address (169.254...) and cannot contact the server.
LVL 21

Accepted Solution

CompProbSolv earned 500 total points
ID: 41778565
OK.... so I misunderstoodd the original post.

You have set up DHCP on the Server 2012 box and it isn't handing out addresses.  If the workstation has a static address then it can ping the Server.  This says that there are no physical obstacles (bad cable, switch, etc.) to DHCP working properly.

It is almost certainly a setting in the DHCP server configuration on the Server 2012 box.  Are you comfortable that you've set it up correctly?  Have you authorized it?  Do you have it listening on all NICs?

To test if it is a firewall issue, turn off the firewall (temporarily) on the Server and run ipconfig /release
ipconfig /renew
on the workstation and see if it gets an IP address.

Author Comment

ID: 41779719
We found the issue, it was a conflict with authorizations within AD, even though this was for a separate LAN. Thanks for pointing us in the right direction!

Featured Post

Free Tool: Port Scanner

Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Understanding the various editions available is vital when you decide to purchase Windows Server 2012. You need to have a basic understanding of the features and limitations in each edition in order to make a well-informed decision that best suits y…
I don't know if many of you have made the great mistake of using the Cisco Thin Client model with the management software VXC. If you have then you are probably more then familiar with the incredibly clunky interface, the numerous work arounds, and …
In this Micro Tutorial viewers will learn how to use Boot Corrector from Paragon Rescue Kit Free to identify and fix the boot problems of Windows 7/8/2012R2 etc. As an example is used Windows 2012R2 which lost its active partition flag (often happen…
This tutorial will walk an individual through the process of installing the necessary services and then configuring a Windows Server 2012 system as an iSCSI target. To install the necessary roles, go to Server Manager, and select Add Roles and Featu…

735 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question