1. On the 2008 DC running DHCP, open the DHCP MMC.
2. Expand DHCP and select DHCP server name.
3. Right Click IPv4
4. Select “Set Predefined Options”
5. Click Add.
6. Name: “Domain suffix search order” (without the quotation marks)
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
– sample1.com,sample2.com,sample3.com
7. Click OK.
8. Close DHCP MMC and restart DHCP Server Service.
9. Reopen DHCP MMC and now scope option 135 is there.
Ref: https://social.technet.microsoft.com/Forums/en-US/d815345e-16e7-4a2d-bf2e-53451d622758/dhcp-scope-option-135-domain-suffix-search-order-in-server-2008?forum=winservergen