DHCP Interoperability with WINS

Applies To: Windows Server 2008

WINS and DNS are both name resolution services for TCP/IP networks. Whereas WINS resolves names in the network basic input/output system (NetBIOS) namespace, DNS resolves names in the DNS domain namespace. WINS primarily supports clients that run older versions of Windows and other applications that use NetBIOS. Windows Vista, Windows Server 2008, Windows XP, Windows Server 2003, and Windows 2000 use DNS names in addition to NetBIOS names. Environments that include some computers that use NetBIOS names and other computers that use domain names must include both WINS servers and DNS servers.

In many cases, you do not need to add WINS servers beyond the number of servers that are planned for DHCP server usage. In many cases, the same server computer can work effectively as both the WINS and DHCP server on your network.

Where a single server is configured as both a WINS server and a DHCP server, it can:

  • Administer a defined scope or superscope range of IP addresses for your network.

  • Serve as the default gateway to provide IP forwarding between adjoining physical networks.

    To set the same default gateway for all DHCP clients located across subnets, assign DHCP option code 3 by using the server computer's IP address as the value in configuring the DHCP scope options.

  • Serve as the primary WINS server for adjoining physical networks.

    To set the WINS server for all DHCP clients located across subnets, assign DHCP option code 44 (a list of IP addresses for WINS servers) and use the server computer's IP address as the value.

    To ensure that WINS is used first by all DHCP clients for NetBIOS name resolution (before broadcast name resolution is tried), assign option code 46 (WINS/NBT node type) to identify the WINS node type as h-node (hybrid node).

When using DHCP and WINS together on your network, consider the following options for interoperation:

  • Use additional DHCP scope options. Use DHCP options to assign WINS node types (option type 46) and to identify WINS servers for use by DHCP clients (option type 44). In some cases, this can involve adjusting these option types for each physical subnet where DHCP and WINS are implemented.

  • Assign a length of time for DHCP lease durations comparable to the time WINS uses for renewal intervals. By default, DHCP leases are 8 days in length and the WINS renewal interval is 6 days. If lease lengths for DHCP differ widely from WINS renewal intervals, the effect on your network can be an increase in lease-management traffic and it might cause a WINS registration for both services. If you shorten or lengthen the DHCP lease time for clients, modify the WINS renewal interval accordingly.

  • Configure all installed connections as routable interfaces. Windows 2000 does not guarantee the binding order for NetBIOS when more than one connection is present and active. All multihomed WINS servers should have their primary IP addresses assigned to each network connection. When configuring a replication partner with the multihomed server as a push or pull partner, you can ensure that the partner always connects to the same adapter on the multihomed server by configuring the partner to refer to the multihomed server using the IP address to which you want the partner to connect. If the partner is configured to refer to the name of the multihomed server instead of a specified IP address, when the replication partner resolves the name to an IP address, it might send WINS packets to the multihomed server using any of its IP addresses.

  • When using DHCP and WINS together on your network, consider using additional DHCP scope options to assign WINS node types and to identify WINS primary and secondary servers for DHCP clients. Adjust the options for each physical subnet where DHCP and WINS are implemented on your network.

Create DHCP reservations for Windows hosts

Statically mapped Windows client computers can be problematic when these computers are not periodically stopped and restarted and their initial registration record in WINS becomes damaged. You can have a more reliable and more manageable network by creating DHCP reservations for domain controllers and domain member servers as DHCP clients with reserved TCP/IP addresses. You can enter a DHCP reservation at the DHCP server using the media access control address of the network adapter installed in the computer. This reservation ensures that the Windows client computer gets the same IP address from the DHCP server each time it starts on the network. You can renew WINS registrations for a DHCP client by typing ipconfig /renew at a command prompt or by restarting the computer; either procedure corrects the offending WINS registration record.

Configure WINS-reliant computers for fault tolerance

For fault tolerance in the case of link failure, configure computers that depend on the WINS service located on other subnets. For their primary WINS server, these clients should point to a local WINS server. For their secondary WINS server, these clients should point to the secondary WINS hub.