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DHCP Search Options

Microsoft Office Communications Server 2007 and Microsoft Office Communications Server 2007 R2 will reach end of support on January 9, 2018. To stay supported, you will need to upgrade. For more information, see Resources to help you upgrade your Office 2007 servers and clients.

To complete unqualified domain name system (DNS) names that will be used to search and submit DNS queries at the client for resolution, you must have a list of DSN suffixes that can be appended to these DNS names. For DHCP clients, this can be set by assigning the DNS domain name option (Option 15) and providing a single DNS suffix for the client to append and use in searches.

In some circumstances it is preferable that a DHCP client be configured by using multiple DNS suffixes, supported with the use of DHCP Search Option 119.

DHCP Search Option 119 is passed from the DHCP server to the DHCP client to specify the domain search list used when resolving hostnames with DNS. DHCP Search Option 119 applies only to DNS and does not apply to other name resolution mechanisms.

Table 1.   DHCP options for domain search list

DHCP Option Description


Specifies the connection-specific DNS domain suffix to be used by the DHCP client.


DNS Domain Search List option to specify the domain search list used when resolving hostnames with DNS.

To enable search option 119 for Windows Server 2003 DHCP server

  1. Open DHCP. (To open DHCP, click Start, point to Settings, click Control Panel, double-click Administrative Tools, and then double-click DHCP.)

  2. In the console tree, click the applicable DHCP server.

  3. On the Action menu, click Set Predefined Options.

  4. In Predefined Options and Values, click Add (Option Class Standard), and then click OK.

  5. In Name, type the string DNS Search List*.*

  6. Set Code to 119 and Data Type string (it is not an array), and then click OK.

  7. Right-click Scope Options, select Configure Options, and then check 119 DNS Search List.

  8. Enter a list of domain suffixes in your organization, delimited by a semicolon (for example,;;

  9. Click OK.