While Velocity supports BungeeCord-style IP forwarding, it is not secure. Users
have a lot of problems setting up firewalls or setting up plugins like IPWhitelist.
Further, the BungeeCord IP forwarding protocol still retains essentially its original
form, when there is brand new support for custom login plugin messages in 1.13.
Velocity's modern IP forwarding uses an HMAC-SHA256 code to ensure authenticity
of messages, is packed into a binary format that is smaller than BungeeCord's
forwarding, and is integrated into the Minecraft login process by using the 1.13
login plugin message packet.
http://openjdk.java.net/jeps/223
Java decided to change their versioning scheme and in doing so modified the
java.version system property to return $major[.$minor][.$secuity][-ea], as
opposed to 1.$major.0_$identifier we can handle pre-9 by checking if the "major"
is equal to "1", otherwise, 9+
of course, it really wouldn't be all that simple if they didn't add a quirk, now would it.
valid strings for the major may potentially include values such as -ea to deannotate a pre release