Configure the DHCP Relay Agent

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Updated: April 30, 2010

Applies To: Windows Server 2008, Windows Server 2008 R2

For a remote access client to obtain an IP address on the intranet to which the VPN server’s LAN adapter is connected, you must configure a DHCP Relay Agent on the VPN server. The relay agent can be configured for IPv4 or IPv6, depending on the type of IP address that the client is configured to receive. For example, if the remote access clients are configured to obtain IPv4 addresses from the VPN server, then you need to configure the DHCPv4 Relay Agent on the VPN server.

The relay agent also transfers DHCPINFORM packets between remote access clients and the DHCP server on the private network to provide the clients with additional information, such as DNS server addresses and IP routes.

To configure the DHCPv4 Relay Agent

Membership in the local Administrators group, or equivalent, is the minimum required to complete this procedure.

  1. Open the Routing and Remote Access MMC snap-in.

  2. In the console tree, expand the server name, and then expand IPv4.

  3. Under IPv4, right-click General, and then select New Routing Protocol.

  4. Select DHCP Relay Agent, and then click OK.

  5. Right-click DHCP Relay Agent, and then select New Interface.

  6. Select the interface that corresponds to the VPN server’s LAN adapter, and then click OK.

  7. On the General tab, make sure that Relay DHCP packets is selected and then, if necessary, select values for Hop-count threshold and Boot threshold.

Note

For information about the configuration settings on the General tab, click For more information on the tab.

  1. Click OK.

  2. Repeat steps 5 through 8 for the interface to which the remote access clients connect.

To configure the DHCPv6 Relay Agent

Membership in the local Administrators group, or equivalent, is the minimum required to complete this procedure.

  1. Open the Routing and Remote Access MMC snap-in.

  2. In the console tree, expand the server name, and then expand IPv6.

  3. Under IPv6, right-click General, and then select New Routing Protocol.

  4. Select DHCPv6 Relay Agent, and then click OK.

  5. Right-click DHCPv6 Relay Agent, and then select New Interface.

  6. Select the interface that corresponds to the VPN server’s LAN adapter, and then click OK.

  7. On the General tab, make sure that Relay DHCP packets is selected and then, if necessary, select values for Hop-count threshold and Elapsed-time threshold.

Note

For information about the configuration settings on the General tab, click For more information on the tab.

  1. Click OK.

  2. Repeat steps 5 through 8 for the interface to which the remote access clients connect.