DhcpSubnetMaskOpt

HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\ interface-name

Data type

Range

Default value

REG_MULTI_SZ

(A space-delimited list of dotted decimal subnet masks.)

(There is no default value for this entry. DHCP configures the value.)

Description

Specifies the subnet mask associated with a Dynamic Host Configuration Protocol (DHCP) option.

The subnet mask stored in the value of this entry is not used for routing. DHCP uses this entry only to test and build the actual subnet mask, which is stored in the value of the DhcpSubnetMask entry.

Tip

This entry is associated with a DHCP option. Configuration data for DHCP options is stored in each HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Dhcp\Parameters\Options\ Option# subkey. The path to this entry is stored in the value of the RegLocation entry in the associated Option# subkey.

To find the DHCP option associated with this entry, use Regedit.exe. From the Edit menu, click Find, and enter the following text: SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\?\DhcpSubnetMaskOpt and select only the Data checkbox.

Caution

The DHCP client service adds this entry to the registry when the service is enabled. The DHCP client service maintains it for internal use. Do not delete this entry or change its value.

Related Entries

DhcpSubnetMask