The dhcp-server packet-distribute giaddr command enables a relay device to forward reply packets based on the GIADDR field.
The undo dhcp-server packet-distribute giaddr command disables a relay device from forwarding reply packets based on the GIADDR field.
By default, a relay device is disabled from forwarding reply packets based on the GIADDR field.
In a scenario where a DHCP client applies for IP addresses from the DHCP server through a relay device, if the DHCP client uses the same MAC address but different sub-interfaces to request for IP addresses in different network segments through the BRAS and DHCP relay, the relay device may send return packets to the BAS user upon receipt of DHCP reply packets from the DHCP server. This is because the MAC address of the BRAS is the same as that of the DHCP relay. As a result, the DHCP relay user fails to go online. To address this problem, run the dhcp-server packet-distribute giaddr command to enable a relay device to determine whether to forward the reply packets sent by the DHCP server to the BAS user or DHCP relay user based on the GIADDR field value.