Supporting relay functionality with a distributed layer 3 gateway

Techniques described herein provide enhanced address allocation services in a network. A switch device in communication with a host device is configured as an address relay device and receives an address request message from the host device. The switch device modifies the address request message to include a response address that uniquely identifies the switch device. The switch device adds in a field of the address request message subnetwork information that identifies a subnetwork to which the host device belongs. The switch device sends the modified address request message to an address server.