@Anurag Bhatia @abhi9822& Perhaps it makes sense to remove the double NAT? Either set the
ONT in bridge mode and let your
D-Link do NAT or let it be as is now, and use the D-Link as a dumb AP? ie just connect the cable from your ONT to one of the LAN ports on the D-Link device, and disable the DHCP server on the D-Link. You'd then need to manage port-forward and other things on the ONT device.