A multihomed DHCP server is a computer running a Windows Server® 2008 operating system that uses the DHCP service for more than a single network connection. For a server computer to be multihomed, each network connection must attach the computer to more than a single physical network. This requires that additional hardware (in the form of multiple installed network adapters) be used on the computer.
A computer running a Windows Server 2008 operating system can perform as a multihomed DHCP server. For multihomed servers, the DHCP service binds to the first IP address statically configured for each network connection in use.
By default, the service bindings depend on whether the first network connection is configured dynamically or statically for TCP/IP. Based on the method of configuration it uses, reflected by its current settings in Internet Protocol (TCP/IP) properties, the DHCP Server service performs default service bindings as follows:
- If the first network connection uses a
manually specified IP address, the connection is enabled in server
bindings. For this to occur, a value for IP address must be
configured and the Use the following IP address option selected in
Internet Protocol (TCP/IP) properties. In this mode, the DHCP
server listens for and provides service to DHCP clients.
- If the first network connection uses an IP
address configured dynamically, the connection is disabled in
server bindings. This occurs when the Obtain an IP address
automatically option is selected in Internet Protocol (TCP/IP)
properties. For computers running Windows Server 2008
operating systems, this is the default setting. In this mode, the
DHCP server does not listen for and provide service to DHCP clients
until a static IP address is configured.
- The DHCP server will bind to the first static
IP address configured on each adapter.
- By design, DHCP server bindings are enabled
and disabled on a per-connection, not per-address basis. All
bindings are based on the first configured IP address for each
connection appearing in the Network Connections folder. If
additional static IP addresses (for example, as set in Advanced
TCP/IP properties) are configured for the applicable connection,
these addresses are never used by DHCP servers running Windows
Server 2008 and are inconsequential for server bindings.
- DHCP servers running Windows Server 2008
never bind to any of the NDISWAN or DHCP-enabled interfaces used on
the server. These interfaces are not displayed in the DHCP console
under the current server bindings list because they are never used
for DHCP service. Only additional network connections that have a
primary static IP address configured can appear in the server
bindings list (or be selectively enabled or disabled there).