@clarknova:
As I recall, if the modem was giving me a 192.168.100.1 address, the lease was very short, like under a minute, in which case pfsense should be getting a proper address very shortly after you reboot your modem. Obviously this is not the case for you.
Not necessarily - the first thing any DHCP client will try is to renew the existing lease when it has one, which the modem will likely accept, and it'll keep on renewing that IP indefinitely.
nojstevens - Your issue isn't related to the firewall at all (any DHCP client would have the exact same issue, it's just taking what it is being assigned), something is causing the modem to assign it an IP rather than one from the ISP. I suspect it's related to your microcell, it's probably picked up your public IP, leaving any other device stuck with a lease from the modem. As for it not doing that initially, initially your firewall won the race to get the public IP. Unpredictable things will happen with a setup like that. Put the microcell behind the firewall, power cycle the modem, don't plug anything else between the modem and the firewall's WAN, and you'll likely be set.
