You can configure a DHCP server IP address on a layer 3 ethernet or subinterface. when an inbound DHCP BOOTREQUEST packet arrives on a port that is member of the port channel, the relay agent forward the packet to the IP address https://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/4_0/dcnm/security/configuration/g uide/sec_dcnm_config/sec_dhcpsnoop.pdf