java socket problem

Francois Tigeot ftigeot at
Tue Jan 13 11:30:32 PST 2015

On Tue, Jan 13, 2015 at 12:20:26PM +0100, Francois Tigeot wrote:
> Java is known to create IPv6 sockets and try to use IPv4 addresses with them.

More explanations:

There has been an official bug report against OpenJDK:

The solution the OpenJDK developers have chosen has been to continue
to use a dual IPv6+IPv4 socket and force IPV6_V6ONLY to 0:

Put another way, they didn't understand anything.

Support for IPv4 addresses in IPv6 sockets has been removed in DragonFly
due to various reasons, including security ones.

More details are available in this document:

As well as in the commit removing v4-mapped addresses support:

Given this situation, I think the best course of action is to remove
IPv6 support from the openjdk packages.

This will at least make Java application usable again with most
production networks.

Francois Tigeot

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