FortiGate DHCP Proxy - FortiGate sets up an IPSec VPN tunnel as a DHCP Proxy
Accurately understanding the difference between DHCP relay and DHCP proxy is very important.
A DHCP relay agent simply relays broadcast DHCP packets to DHCP server located in other subnets whenever it receives packets from a DHCP client residing in that same subnet. On the other hand, a DHCP proxy agent not only relays the DHCP packets between subnets, but also acts on behalf of a DHCP server, while also acting as a DHCP client. That is, it acts as a DHCP server to the DHCP client, but as a DHCP client to the DHCP server.
This video will demonstrate how to use FortiClient to establish an IPSEC VPN tunnel with a FortiGate. Additionally, The FortiGate acts as a DHCP proxy, acquiring an IP addresses for the VPN clients from an external DHCP server.