This is a simple program to test ipv6 network connection with your jre.

Compile the code and get the jar from build/libs/, then execute it: java -jar NetworkConnectionTest.jar

For test purpose, I added Thread.sleep(20000);, so it will first stuck for 20s.

Default test address is [2001:470:1:18::115]:80 (is ipv6.test-ipv6.com).

You can change test address in command line argument:

java -jar NetworkConnectionTest.jar [host] [port]

or through system property:

java -DtestHost=<host> -DtestPort=<port> NetworkConnectionTest.jar

that's all!

the Minecraft mod version required Fabric Loader 0.15.7+ to load, and it will quit the game after test has completed. nothing else excepts.