Server 2012 with two NICs, one getting internet, one is DHCP

I have a network set up like this:

There's a pfsense firewall, with WAN adapter IP 10.0.40.81 and LAN IP 192.168.1.1/24. The box is functioning correctly as a firewall and NAT, as far as I can tell: I can get internet through NIC1 on my DHCP server, through static IP 192.168.1.2.

There is a second NIC on the DHCP server, 172.16.0.1/24, no gateway, that does the actual leasing. It is handing out leases correctly, but the clients are not able to connect to the internet. I suspect this is because, when I look at Network and Sharing Center on my DHCP server, NIC2 has "Limited Connectivity" (no Internet). Am I supposed to use ICS to allow my 172.16.0.1 adapter to get internet through my 192.168.1.2 adapter? The clients of the DHCP server can resolve DNS names, but they have no internet.

pfsense firewall

--> DHCP server NIC 1, with a static IP of 192.168.1.2, netmask /24, gateway 192.168.1.1
--> DHCP server NIC 2, static IP 172.16.0.X, netmask /24, no gateway

----->DHCP clients, correctly receiving 172.16.0.x addresses, can resolve DNS, no internet though

All of these devices are connected to a Cisco switch.

Current DHCP sever settings:

ROUTER: 172.16.0.1

DNS Servers:172.16.0.1 (DHCP server is also running DNS)

WINS/NBNS Servers" 172.16.0.1

I am unsure about the ROUTER part... I also tried 192.168.1.2, but either way DHCP clients can resolve an IP with no internet.