With Avast shields disabled, CanYouSeeMe.org - Open Port Check Tool returns "no route to host". With Avast shields enabled, it always returns that the connection timed out.
The laptop is behind a WOW cable modem and I opened the port as a virtual server, which is required on the Arris to port forward, while talking with WOW customer support. There is no secondary router. This is the first time I have installed the Pocketmine server on this machine, so that is no prior history. It works fine across the wireless LAN.
Using Avast Internet Security 8.0.2011 with engine and virus last updated 5 minutes ago.