DHCP Confusing / Problematic on OpenVPN Interface

[tristano]

I have pfSense RC2 configured with LAN and OpenVPN interfaces on individual subnets. Here are some relevant settings:

VPN >> OpenVPN
    Server (tunnel)
        Protocol:      UDP
        Dynamic IP:    yes
        Local port:    1194
        Address pool:  192.168.24.0/23

Services >> DHCP Server
    LAN
        Enable DHCP:    yes
        Subnet:        192.168.16.0
        Subnet mask:    255.255.248.0
        Range:          192.168.22.100 to 192.168.23.199
    VPN_open
        Enable DHCP:    ?
        Subnet:        192.168.24.0
        Subnet mask:    255.255.254.0
        Range:          192.168.24.100 to 192.168.25.199

If the DHCP Server is not enabled on the VPN interface, connecting clients still seem to get DHCP service and are assigned an address on the 192.168.24.0/23 subnet. If the DHCP Server is enabled on the VPN interface, however, DHCP service on the LAN subnet is interrupted and only static clients and fixed leases seem to get onto the network. The obvious solution is to disable the DHCP Server on the VPN interface, but this seems counterintuitive. Any thoughts?

Tristan Olive