I was trying it at the office, which was through a switch — definitely possible that there was a firewall, but I’m unable to gain access to the switch to figure out if it got DHCP. (DHCP is definitely turned on, however, as all the other computers get an address no problem).
Tried at home too, plugged directly into my modem/router combo. Now it’s flashing two times. I *do* have access to the control panel for this router and I can’t confirm whether or not it’s actually getting DHCP from the router as the MAC address of the Leaf isn’t showing up in the DHCP clients list, and none of the IP addresses in the list are responding to pings apart from the known computers.