Export (0) Print
Expand All

Troubleshooting DHCP clients

Updated: January 21, 2005

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Troubleshooting DHCP clients

What problem are you having?

The DHCP client does not have an IP address configured or indicates that its IP address is
  • Cause:  The client was not able to contact a DHCP server and obtain an IP address lease, either because of a network hardware failure or because the DHCP server is unavailable.

  • Solution:  Verify that the client computer has a valid functioning network connection. First, check that related client hardware (cables and network adapters) are working properly at the client using basic network and hardware troubleshooting steps.

    If the client hardware appears to be prepared and functioning properly, check that the DHCP server is available on the network by pinging it from another computer on the same network as the affected DHCP client.

The DHCP client appears to have automatically assigned itself an IP address that is incorrect for the current network.
The DHCP client appears to be missing some network configuration details or is unable to perform related tasks, such as resolving names.
  • Cause:  The client might be missing DHCP options in its leased configuration, either because the DHCP server is not configured to distribute them or the client does not support the options distributed by the server.

  • Solution:  For Microsoft DHCP clients, verify that the most commonly used and supported options have been configured at the server, scope, client, or class level of options assignment.

  • See also:  Manage Options and Classes; Assigning options

The DHCP client appears to have incorrect or incomplete options, such as an incorrect or missing router (default gateway) configured for the subnet on which it is located.
  • Cause:  The client has the full and correct set of DHCP options assigned but its network configuration does not appear to be working correctly.

    If the DHCP server is configured with an incorrect DHCP router option (option code 3) for the default gateway address of the client, clients running Windows NT, Windows 2000, or Windows XP use the correct address. However, DHCP clients running Windows 95 use the incorrect address.

  • Solution:  Change the IP address list for the router (default gateway) option at the applicable DHCP scope and server. If you are configuring the router option as a Server Option at the affected DHCP server, remove it there and set the correct value in the Scope Options node for the applicable DHCP scope that services the client.

    In rare instances, you might have to configure the DHCP client to use a specialized list of routers different from other scope clients. In such cases, you can add a reservation and configure the router option list specifically for the reserved client.

  • See also:   Assign a server-based option; Assign a scope-based option; Assign an option to a reserved client; Add a client reservation; Assigning options

    For more information about DHCP options, see "DHCP Options" at the Microsoft Windows Resource Kits Web site.

Many DHCP clients are unable to get IP addresses from the DHCP server.
  • Cause:  The IP address of the DHCP server was changed and now DHCP clients cannot get IP addresses.

  • Solution:  A DHCP server can only service requests for a scope that has a network ID that is the same as the network ID of its IP address.

    Make sure that the DHCP server IP address falls in the same network range as the scope it is servicing. For example, a server with an IP address in the network cannot assign addresses from scope unless superscopes are used.

  • See also:  DHCP Best Practices; Using superscopes; Configuring scopes

  • Cause:  The DHCP clients are located across a router from the subnet where the DHCP server resides and are unable to receive an address from the server.

  • Solution:  A DHCP server can provide IP addresses to client computers on remote multiple subnets only if the router that separates them can act as a DHCP relay agent.

    Completing the following steps might correct this problem:

  1. Configure a BOOTP/DHCP Relay Agent on the client subnet (that is, the same physical network segment). The relay agent can be located on the router itself, on a computer running Windows NT Server and the DHCP Relay Agent component, on a computer running Windows 2000 Server with the Routing and Remote Access service enabled and configured as a DHCP Relay Agent, or on a computer running a Windows Server 2003 operating system with the Routing and Remote Access service enabled and configured as a DHCP Relay Agent.

  2. At the DHCP server, do the following:

    1. Configure a scope to match the network address on the other side of the router where the affected clients are located.

    2. In the scope, make sure that the subnet mask is correct for the remote subnet.

    3. Use a default gateway on the network connection of the DHCP server in such a way that it is not using the same IP address as the router that supports the remote subnet where the clients are located.

    4. Do not include this scope (that is, the one for the remote subnet) in superscopes configured for use on the same local subnet or segment where the DHCP server resides.

  3. Make sure there is only one logical route between the DHCP server and the remote subnet clients.

  • See also:  DHCP Best Practices; DHCP/BOOTP Relay Agents; BOOTP and DHCP

  • Cause:  Multiple DHCP servers exist on the same local area network (LAN).

  • Solution:  Make sure that you do not configure multiple DHCP servers on the same LAN with overlapping scopes.

    You might want to rule out the possibility that one of the DHCP servers in question is a computer running Small Business Server. On a computer running Small Business Server, the DHCP Server service automatically stops when it detects another DHCP server on the LAN.

  • See also:  DHCP Best Practices; Configuring scopes

The DHCP client appears to be affected by another problem not described above.

Community Additions

© 2016 Microsoft