DHCP-Relay over ipsec

Hi All!! I have 5 networks connected to one central network over ipsec. Each network has a different ip family 192.168.x.0/24. I want to configure a DHCP server in the central network to serve all the networks. I only have to install a DHCP-Realy in each gateway of each network and configure the DHCPSERVER="192.168.0.10" for example, or not? I found the DHCP-Relay software in: http://www.strongsec.com/freeswan/dhcprelay/ Is this the best to use? Thanks!!