Configuring the BOOTP and DHCP reply source address

You can configure the device so that a BOOTP/DHCP reply to a client contains the server IP address as the source address instead of the router IP address.
  1. Enter the global configuration mode by issuing the configure terminal command.
    device# configure terminal
  2. Enter the ip helper-use-responder-ip command.
    device(config)# ip helper-use-responder-ip