WiFi dropped connection and no longer works

My Echo dropped its WiFi connection, and is unable to reconnect to my network. I manage my own network, and have changed nothing on any configuration. In fact, my MAC filtering explicitly allows this device to connect, and I even have an IP address reserved for it (Echo gets it's address via DHCP, I assume). Absolutely nothing I do can get it to connect, and I have performed a hard reset on the device as well as made sure my router firmware is on the most current version. I also power cycled my router, to rule out anything obvious. The only thing I can imagine is maybe the device isn't being allowed through a specific port to connect to Amazon's servers? Not sure what port it might be trying to use. Any insights out there? Things I may have overlooked?