Monday, September 19, 2011

DNS Suffix Search Order via DHCP

I was recently working on a new parallel domain with one of the members of my team and the issue of DNS Suffix Search Order came up. The search order had to be set to include the parallel domain, the primary domain and a number of other things.

I was adamant that the search order could be set by DHCP as well as by GPO, but I couldn't specifically remember the details. My engineer pointed me to this Microsoft Knowledge Base article that states:
The following methods of distribution are not available for pushing the domain suffix search list to DNS clients:
  • Dynamic Host Configuration Protocol (DHCP). You cannot configure DHCP to send out a domain suffix search list. This is currently not supported by the Microsoft DHCP server.
Fortunately, an engineer from another department came to the rescue with DHCP Option 135. This can be added in Windows Server 2008 as follows (I believe this originated in a TechNet post):

1. On the 2008 Server running DHCP, open the DHCP MMC.
2. Expand DHCP and choose the DHCP server name.
3. Right click on IPv4
4. Choose "Set Predefined Options"
5. Click on Add.
6. Name: "Domain suffix search order"
Data Type: String
Code: "135" (without the quotation marks)
Description: "List of domain suffixes in order" (without the quotation marks)
String: enter your search suffixes separated by comma with no spaces,,

7. Click onto the OK to save changes .
8. Exit the DHCP MMC and restart the DHCP Server Service.
9. Open the DHCP MMC again and now scope option 135 is a listed option.