IPv4 Non-Configurable Registry Settings

2/15/2013

This section describes registry values that are created and used internally by TCP/IP. They should never be modified by using Registry Editor. They are listed here for reference only.

The following table shows the non-configurable registry values for the HKEY_LOCAL_MACHINE\Comm\Tcpip\Parms registry key.

Value : type Description

DNSDomain : REG_SZ

It specifies the latest domain name, configured by the DHCP server, that is used by the network to which the device is connected. This value can be any domain name, such as example.microsoft.com.

The following table shows the non-configurable values for the HKEY_LOCAL_MACHINE\Comm\<Adapter Name>\Parms\Tcpip subkey.

Value : type Description

DhcpDefaultGateway : REG_MULTI_SZ

This value specifies the list of default gateways to be used to route packets not destined for a subnet to which the device is directly connected and for which a more specific route does not exist. This value can be any set of valid IP addresses.

This value is written by the DHCP client service, if it is enabled. It is overridden by a valid DefaultGateway value. Even though this value is set on a per-interface basis, there is always only one default gateway active for the device. Additional entries are treated as alternatives to use if the first one is detected as down.

DhcpDNS : REG_MULTI_SZ

This value specifies the IP address of the DNS name server. This value can be any valid IP address. Two DNS servers can be specified.

DhcpIPAddress : REG_MULTI_SZ

This value specifies the DHCP-configured IP address for the interface. It can be any valid IP address.

DhcpServer : REG_MULTI_SZ

This value specifies the IP address of the DHCP server that granted the lease on the IP address in the DhcpIPAddress value. This value can be any valid IP address.

DhcpSubnetMask : REG_SZ

This value specifies the DHCP-configured subnet mask for the address specified in the DhcpIPAddress value. The mask can be any subnet mask that is valid for the configured IP address.

DhcpWINS : REG_MULTI_SZ

This value specifies the IP address of the WINS name server. This value can be any valid IP address. Two WINS servers can be specified.

Domain : REG_SZ

This value specifies the adapter-specific DNS domain name that is configured by the DHCP server.

Lease : REG_DWORD

This value is used by a DHCP client service to store the time, in seconds, for which the lease on the IP address for this adapter is valid. The valid range for this value is 1-0xFFFFFFFF (hexadecimal).

LeaseObtainedHigh : REG_DWORD

This value is used by a DHCP client service to store the time (high) at which the lease on the IP address for this adapter was obtained. The valid range for this value is 1-0xFFFFFFFF (hexadecimal).

LeaseObtainedLow : REG_DWORD

This value is used by a DHCP client service to store the time (low) at which the lease on the IP address for this adapter was obtained. The valid range for this value is 1-0xFFFFFFFF (hexadecimal).

LeaseTerminatesTime : REG_DWORD

This value is used by a DHCP client service to store the time at which the lease on the IP address for this adapter will expire. The valid range for this value is 1-0xFFFFFFFF (hexadecimal).

T1 : REG_DWORD

This value is used by a DHCP client service to store the time at which the service will first try to renew the lease on the IP address for the adapter by contacting the server that granted the lease. The time is based on the number of seconds since the lease was obtained. For example, for a three-day lease, T1 is 0.875 x 36 hrs (0x000375F0). The valid range for this value is 1-0xFFFFFFFF (hexadecimal).

T2 : REG_DWORD

This value is used by a DHCP client service to store the time at which the service will try to renew the lease on the IP address for the adapter by broadcasting a renewal request. The time is based on the number of seconds since the lease was obtained. Time T2 should only be reached if the service was unable to renew the lease with the original server for some reason. For example, for a three-day lease, T2 is 0.875 x 36 hrs (0x000375F0). The valid range for this value is 1-0xFFFFFFFF (hexadecimal).

Non-configurable device name values are also included in the HKEY_LOCAL_MACHINE\Ident key. For more information, see IPv4 Device Name Registry Settings.

See Also

Reference

IPv4 Registry Settings
IPv4 Configurable Registry Settings
IPv4 and IPv6 Common Registry Settings