Unicast IP Routing

Troubleshooting the DHCP Relay Agent

If the Windows 2000 DHCP Relay Agent is not providing relay services for DHCP clients on a network, check for the following:

Verify that the interface on the Windows 2000 Router that connects to the network where the DHCP clients are located is added to the DHCP Relay Agent IP routing protocol.
Verify that the Relay DHCP packets check box is selected for the DHCP Relay Agent interface connected to the network where the DHCP clients are located.
Verify that the IP addresses of DHCP servers configured on the global properties of the DHCP Relay Agent are the correct IP addresses for DHCP servers on your internetwork.
From the router with the DHCP Relay Agent enabled, use the PING utility to ping each of the DHCP servers configured in the global DHCP Relay Agent dialog. If you cannot ping the DHCP servers from the DHCP Relay Agent router, troubleshoot the lack of connectivity between the DHCP Relay Agent router and the DHCP server or servers.
Verify that IP packet filtering is not preventing the receiving (through input filters) or sending (through output filters) of DHCP traffic. DHCP traffic uses the UDP ports of 67 and 68.
Verify that TCP/IP filtering on the router interfaces is not preventing the receiving of DHCP traffic.