DHCP refers to Dynamic Host Configuration Protocol. Basically, it’s a mechanism that assigns IP addresses to computers dynamically. DHCP is a role (service) running on a server machine in the network in order to assign dynamic IP addresses to hosts. For some information on BOOTP Vendor Extensions and DHCP Options, see the following link and for automatic IP Assignment, see the following guide Dynamic Host Configuration Protocol (DHCP). Here are some other vital links “how to install Dynamic Host Configuration Protocol on Windows Server 2019, and how to configure DHCP: Post-deployment of Dynamic Host Configuration Protocol“. You may also be interested in this guide “How to deploy Windows using ADK, MDT, and WDS“. In this article, you will learn about the WDS and DHCP Deployment Scenarios: Configure DHCP Options 60, 66, and 67.
Why do we need DHCP Options?
DHCP options enable administrators to specify additional DHCP parameters in the form of pre-defined, vendor-specific information that is stored in the options field of a DHCP message. When the DHCP message is sent to clients on the network, it provides vendor-specific configuration and service information. Learn more about DHCP from this link.
WDS also supports unicast, multicast transmissions, and scheduled casting. By using multicast, we can send one image over the network to multiple computers. With scheduled casting, we can transfer images at a certain time or after a certain number of computers have contacted the WDS server. This way we can deploy our images at off-peak times. We can configure our WDS server to respond to clients in three different ways.
- Not Respond: We can enable this if we don’t want the WDS to respond to client requests.
- Respond to Known: In this method, Active Directory (AD) needs to be available. All devices should be able to contact WDS. This way we can prevent unknown computers from accessing WDS. For devices that are not part of the Domain, they can be pre-staged. By pre-staging our devices, we pre-create the computer account in AD with the relevant names, therefore when the pre-staged computer contacts WDS, it will supply its existing computer name and in this way the WDS server will allow the imaging process.
- Respond to All: Any computer that requests the image from WDS will receive the image.
Configure DHCP Options
To configure the DHCP options, launch the DHCP Manager as shown below. From the Server Manager, there are two ways to launch this. Simply click on the Tool menu and Select Server Manager or right-click on the DHCP server node, on the server, it is installed. Click on DHCP Manager.
This will open the DHCP Console as shown below. Expand the DHCP server
– Expand IPv4 and click on Server Option. Then, click on Configure Options
This will open the DHCP Server options as shown below
Note: The Server Option 60 was enabled by default on the screen above, see the scenario one for more details. This is because you have your DHCP server and WDS running on the same host.
Scenario 1 – WDS and DHCP Deployment Scenarios
WDS and DHCP on the same server (Clients will find WDS through option 60 in DHCP): For us, this is enough since I have my WDS and DHCP on the same server. The reason it is selected by default.
Scenario 2 – WDS and DHCP Deployment Scenarios
WDS and DHCP in different subnets, you will need to clients will find WDS through Options 66 and 67 set in DHCP.
- Option 66 tells the client the name of the WDS server.
- Option 67 tells the client which file to boot from.
Scenario 3 – WDS and DHCP Deployment Scenarios
WDS and DHCP server on the same subnet but different servers: Here the clients will find the WDS by broadcast. To get PXE working on a server that is running both DHCP and WDS you need to enable options 66 and 67. These settings will help your connecting clients to find the appropriate PXE server.
The setting is found in the DHCP configuration manager window.
- Expand IPv4 and
- Right-click and select Configure Options, and
- Scroll down and select the following options below.
066 Boot Server Host Name 067 Bootfile Name
For Option 066 Boot Server Host Name
Enter the string value in the field for “066 Boot Server Host Name”. You can enter the FQDN of your server or the IP Address of the server in the string below.
For Option 067 Bootfile Name
Click on 067 Bootfile Name as shown below. Enter the string ” \smsboot\x64\wdsnbp.com” in the field. Click on Apply and if you have other settings to enter, click on apply otherwise click on OK.
Where is the BootFile Name located ” \smsboot\x64\wdsnbp.com”?
Navigate to the Remote Installation Folder location on the drives. The folder contains the boot images, install images, Windows Deployment Services Management Tool, and PXE Boots. This drive MUST be NTFS formatted. See the image below for the location of the bootfile.
For how to configure Windows Deployment Services on Windows Server 2019″ see the link. Now all the needed server options to support WDS has been successfully configured. I had to configure options 66 and 67 just to demonstrate how this works. It does not apply to scenario 1. I only need option 60 as I have both my WDS and DHCP server on the same device.
Note: If you have WDS and DHCP on the same server. Clients will find WDS through option 60 in DHCP). For this, we do not need our server to listen to options 67 and 66. This is why option 60 was selected by default. For this, you can see the WDS settings for DHCP below.
What happens when WDS and DNS are installed on the same server: DNS issues with WDS, to resolve this, see the following link.
I hope you found this blog post helpful. Now you have learned the various WDS and DHCP Deployment Scenarios: Configure DHCP Options 60, 66, and 67. If you have any questions, please let me know in the comment session.