IPv6 connectivity issues
have a Galaxy S4 on verizon, and have a dual-stack IPv6-enabled LAN with Comcast-provided prefix delegation from the router. Every other device - Windows/Mac/Linux computers, iphones/ipads, Lumia 2520 windows tablet - has no problem pulling addresses & connecting to each other either using the link-locals or the global addresses. Except for Android. Using the app "IPv6 and more", it shows me pulling a proper IPv6 global address, but using the ping/trace tools in this app I am unable to connect to any other host on the LAN. I CAN connect to global addresses outside the LAN. The app (which looks pretty substandard IMHO) apparently runs 2 tests, "via API" and "commandline". The API shows any other LAN address as "NOT reachable". Global addresses on the internet show "reachable" via API, but still not from commandline. Additionally, the ES file explorer has the same problem connecting to LAN hosts; it can connect fine to an IPv6 FTP server i've setup elsewhere, but has no access internally.
Any idea what's going on? Is IPv6 LAN access broken in Android?