Cisco CCNA 200-301 Practice Question

To enable devices on VLAN 10 to obtain their IP configurations from a DHCP server on a different subnet, the correct command is ip helper-address [DHCP server IP address] applied to the router interface connected to VLAN 10. This command configures the router to forward DHCP broadcasts (and certain other UDP broadcasts) to the specified IP address, effectively acting as a DHCP relay agent. The other options are incorrect because they either refer to non-existent commands or do not perform the DHCP relay function. For example, ip dhcp relay-address and ip dhcp-server are not valid Cisco IOS commands in this context, and ip relay does not exist.