This how-to article explains the process to add the necessary DHCP scope option 156 to a Windows Server 2008 R2 DHCP server for use with ShoreTel IP phones. This process assumes that you have already created a DHCP scope and is made up of two main steps.

Step One – Creating Option 156 in Your Windows DHCP server.

1. Open the DHCP tool in Windows – Start>Administrative Tools>DHCP
2. Add all of the Windows DHCP servers to the manager – Right-click DHCP>Add Server… Select This authorized DHCP server and add all the servers by clicking the first, pressing and holding the Shift key and clicking the last server. Click OK.
3. Click the “+” sign next to the first DHCP server in the left-most pane to expand the options. Right-click IPv4 and select Set Predefined Options.
4. Click Add and in the Name field, type Shoretel (or whatever you want to name the option).
5. Set the Data type to String.
6. Under Code, type 156 and add a description if desired.
7. Click OK twice.

Step Two – Adding Option 156 to Your Windows DHCP Server’s DHCP scope.

1. Click the “+” sign next to IPv4, then next to Scope [x.x.x.x] (where x.x.x.x is your scope subnet and name).
2. Right-click Scope Options and select Configure Options.
3. On the General tab, scroll down to option 156 and check the box next to it to enable it.
4. Under the String Value,enter any/all of the following options: ftpservers=x.x.x.x, country=1, language=1, vlanid=n (where x.x.x.x is your ShoreWare Headquarters server’s IP address and n is the VLAN for your ShoreTel IP phones).
5. Click OK.

Repeat this process for any other Windows DHCP servers or activated scopes that will be assigning IP addresses to your ShoreTel IP phones.