The other kind of deployment of DHCP Relay in IP Fabric is where the DHCP Relay is installed on each and every leaf node in the fabric.
In this deployment, the DHCP Client broadcasts the DHCPDISCOVER packets through the network. When the packet is received by the DHCP Relay, that node in the MCT pair, that receives this packet, forwards the DHCPDISCOVER packet to the DHCP Server through the Border Leaf.
Since the DHCPDISCOVER packet is a broadcast packet, the DHCP Relays also broadcast these packets to the same broadcast domain from where the packet was received. This could cause flooding and looping within the network.
The ip dhcp relay disable-flooding command must be configured on each of the DHCP Relays to prevent flooding. When enabled, this command prevents the DHCP Relays from re-broadcasting the received Layer 2 DHCPDISCOVER packet. For more information, see Prevent Flooding of Broadcast Packets from the DHCPv4 Relay Agent.