HP 6125XLG R2306-HP 6125XLG Blade Switch Layer 3 - IP Services Command Referen - Page 71

DHCP relay agent commands dhcp relay check mac-address Use dhcp relay check mac-address to enable MAC address check on the relay agent. Use undo dhcp relay check mac-address to disable MAC address check on the relay agent. Syntax dhcp relay check mac-address undo dhcp relay check mac-address Default The MAC address check function is disabled. Views Interface view Predefined user roles network-admin Usage guidelines With this function enabled, the DHCP relay agent compares the chaddr field of a received DHCP request with the source MAC address in the frame header. If they are the same, the DHCP relay agent forwards the request to the DHCP server. If they are not the same, the DHCP relay agent discards the DHCP request. The MAC address check function takes effect only when the dhcp select relay command has been configured on the interface. A DHCP relay agent changes the source MAC addresses of DHCP packets before forwarding them out. Therefore, enable the MAC address check function only on the DHCP relay agent directly connected to the DHCP clients. If you enable this feature on an intermediate relay agent, it may discard valid DHCP packets and the sending clients will not obtain IP addresses. Examples # Enable MAC address check on the relay agent. system-view [Sysname] interface vlan-interface 10 [Sysname-Vlan-interface10] dhcp relay check mac-address Related commands dhcp select relay dhcp relay client-information record Use dhcp relay client-information record to enable recording client information in relay entries. A relay entry contains information about a client such as the client's IP and MAC addresses. Use undo dhcp relay client-information record to disable the function. 63