Configuring the source IP address of a DHCP client packet on the DHCP relay agent

Enables the DHCP server to know the source subnet or network of a DHCP-client packet.

By default, a DHCP relay agent forwards a DHCP client packet with the source IP address set to the IP address of the outgoing interface to the DHCP server. You can configure ACLs on a DHCP server to provide or block DHCP services to particular subnets or networks. The ip bootp-use-intf-ip command configures a DHCP relay agent to set the source IP address of a DHCP client packet with the IP address of the incoming interface for the packet. This reveals the source subnet or network of a DHCP client packet to the DHCP server and enables the DHCP server to process or discard the DHCP traffic according to the configured ACLs.

Enter the ip bootp-use-intf-ip command in global configuration mode of the DHCP relay agent.
device(config)# ip bootp-use-intf-ip