How can I disable IPv6 stack use for IPv4 IPs on JRE?

Question

As you can see on below screenshots, eclipse and Android SDK Manager (and other Java programs) are trying to connect to a IPv4 Internet IP via IPv6 TCP/IP stack while Proxif

Answer 1

Maybe a bit late but for me neither solution worked. So I included this option as it is stated here:

-Djava.net.preferIPv4Addresses=true

But also the followingI added line to the end of the file /etc/sysctl.conf

net.ipv6.conf.all.disable_ipv6 = 1

And

sudo sysctl -p

as it is explained here. In order to check that ipv6 is disabled just execute:

ip a | grep inet

Answer 2

Did you try (from the command line)

-Djava.net.preferIPv4Stack=true

or (from your code)

System.setProperty("java.net.preferIPv4Stack" , "true");

Answer 3

I wanted to use this for some program I hadn't control for running that Java app so ended with this _JAVA_OPTIONS=-Djava.net.preferIPv4Stack=true environment variable. (read about _JAVA_OPTIONS here)

If you are using Windows, just run this command on Windows cmd:
setx _JAVA_OPTIONS -Djava.net.preferIPv4Stack=true

Thanks to Jason Nichols for reminding this JVM argument :)