IPv4 and IPv6 Non-Configurable Registry Settings (Compact 2013)

3/26/2014

This section describes registry values that are created and used internally by TCP/IP. They cannot be modified by using Registry Editor. They are listed here for reference only.

Read-Only Registry

IPv4

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.

IPv4, Adaptor/Interface Specific

The following table shows the read-only 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. The following table shows the values for the HKEY_LOCAL_MACHINE\Ident registry key. This key identifies the device. A configurable Name value is defined for this key, but the other settings are non-configurable.

Value : type

Description

Desc: REG_SZ

This value provides a description for the device.

Name: REG_DWORD

This value provides the device name, supplied by the OEM.

OrigName: REG_DWORD

This value stores the name of the device at the time when the device was started. When the device is started, this value is automatically created and set to "WinCE". If a Name value exists, it is copied to the OrigName value.

An application can only modify the OrigName value by using sethostname.

IPv6 DHCP Read-Only

This section describes registry values that are created and used internally by the Dynamic Host Configuration Protocol for IP version 6 (DHCPv6) client. DHCPv6 is a client/server protocol that automatically provides an Internet Protocol (IP) host with its IP address and other related information such as the subnet mask and default gateway. Windows Embedded Compact 2013 provides a DHCPv6 client that you can enable through a configurable registry setting (see DHCPv6 Configurable Registry Settings for more information about enabling or disabling the DHCPv6 client). The DHCPv6 client is enabled by default.

The following table shows the non-configurable DHCPv6 values for the HKEY_LOCAL_MACHINE\Comm\<Adapter Name>\Parms\Tcpip registry key. The DHCPv6 client creates and updates these values when it runs. You cannot change these values, but you can read them to get DHCPv6 configuration information.

Name

Description

DhcpV6DNS : REG_MULTI_SZ

The IPv6 addresses of one or more DNS name servers configured by the DHCPv6 server.

DhcpV6Domain : REG_SZ

The latest domain name, configured by the DHCPv6 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.

DhcpV6DomainList : REG_MULTI_SZ

List of adapter-specific DNS domain names reported by the DHCPv6 server.

DhcpV6Iaid : REG_DWORD

Identity association identifier (IAID). Each identity association has an IAID, which is unique among all IAIDs for identify associations (IAs) belong to this DHCPv6 client. The DHCPv6 client generates a unique IAID for each network interface on your device. For more information about identity associations and IAIDs, see RFC 3315.

Dhcpv6IanaAddr : REG_BINARY

The network interface IPv6 address configured by the DHCPv6 server. The IPv6 type of this address is IANA (Identity Association for Non-temporary Addresses).

Dhcpv6IanaIaids : REG_BINARY

This value contains a list of IAIDs used by the DHCPv6 client. The structure of this data is opaque outside of the DHCPv6 client.

Dhcpv6IanaLeases : REG_BINARY

This value contains a list of IANA IPv6 addresses leased by the DHCPv6 client. The structure of this data is opaque outside of the DHCPv6 client.

Dhcpv6InterfaceOptions : REG_BINARY

This value contains a binary structure of interface options used by the DHCPv6 client. The structure and content of this data is opaque outside of the DHCPv6 client.

Dhcpv6IsUnicastEnabled : REG_DWORD

Boolean value that indicates whether unicast mode is enabled. In unicast mode, only one network interface uses the assigned IPv6 address.

  • 1 = Unicast mode is enabled; only one interface may use the assigned IPv6 address.
  • 0 = Unicast mode is disabled; multiple interfaces may use the assigned IPv6 address.

Dhcpv6LeaseObtainedTime : REG_DWORD

The time, in seconds, for which the lease on the IPv6 address for this adapter is valid. The time value is the number of seconds since 00:00:00, January 1, 1970, GMT. The valid range for this value is 1-0xFFFFFFFF (hexadecimal).

Dhcpv6MaxLeaseExpireTime : REG_DWORD

The time at which the lease on the IPv6 address for this adapter will expire. The time value is the number of seconds since 00:00:00, January 1, 1970, GMT. The valid range for this value is 1-0xFFFFFFFF (hexadecimal).

Dhcpv6ServerDUID : REG_BINARY

The DHCP Unique Identifier (DUID) of the DHCPv6 server.

Dhcpv6ServerPreference : REG_DWORD

The server preference option value reported in the DHCPv6 Server ADVERTISE message. The valid range for this value is 0 (zero) to 255.

Dhcpv6State : REG_DWORD

A bit mask specifying the state of the DHCPv6 client. This value is a bitwise OR of zero or more of the following flags.

ValueDescription
0x00000002The DHCPv6 client has contacted the DHCPv6 server through this interface.
0x00000010DHCPv6 is enabled on this interface.
0x00000020The interface is in stateless mode.
0x00000180Mask (two bits) for the media state of the interface. When the media state is 0, the interface is connected. When the media state is 1, the interface is reconnected. When the media state is 2, the interface is disconnected.
0x00000200Power was resumed on this interface.

Dhcpv6T1 : REG_BINARY

The renewal time for the prefix, in seconds.

Dhcpv6T2 : REG_BINARY

The rebind time of the prefix, in seconds

See Also

Other Resources

TCP/IP