Dell Force10 MXL Blade MXL 10/40GbE Switch IO Module Configuration Guide - Page 169

Debug DHCP Server To display debug information, follow this step: Task Display debug information for DHCP server. Command Syntax Command Mode debug ip dhcp server [events | packets] EXEC Privilege DHCP Clear Commands To clear DHCP binding entries, follow these steps: Task Command Syntax Clear DHCP binding entries for the entire binding clear ip dhcp binding table. Clear a DHCP binding entry for an individual IP address. Clear a DHCP address conflict. clear ip dhcp binding ip address clear ip dhcp conflict Clear DHCP server counters. clear ip dhcp server statistics Command Mode EXEC Privilege EXEC Privilege EXEC Privilege EXEC Privilege Configure the System to be a Relay Agent DHCP clients and servers request and offer configuration information using broadcast DHCP messages. Routers do not forward broadcasts, so if there are no DHCP servers on the subnet, the client does not receive a response to its request and therefore cannot access the network. You can configure an interface on the Dell Force10 system to relay the DHCP messages to a specific DHCP server using the ip helper-address dhcp-address command from INTERFACE mode (Figure 9-4). Specify multiple DHCP servers by entering the ip helper-address dhcp-address command multiple times. When you configure the ip helper-address command, the system listens for DHCP broadcast messages on port 67. The system rewrites packets received from the client and forwards it using unicast; the system rewrites the destination IP address and writes its own address as the relay device. Responses from the server are unicast back to the relay agent on port 68, and the relay agent rewrites the destination address and forwards the packet to the client subnet using broadcast. Note: DHCP relay is not available on Layer 2 interfaces and VLANs. Dynamic Host Configuration Protocol (DHCP) | 167