For the record and I am hoping this may help.

There was an OLD problem with IPV4 many years back. What would happen is
a successively slower transmission of IP packets. I don't know the fix
as I solved the problem for a couple customers another way.

This was back in Borland days of Interbase and I suspect it was
something to do with the configuration of the port.

Good luck.

On Thu, 2014-08-28 at 20:05 +0200, Mark Rotteveel mark@...
[Firebird-Java] wrote:

>
> On 28-8-2014 09:54, hugo.larson@... [Firebird-Java] wrote:
> > I have a problemen since the early days of firebird and Jaybird.
> > I'm now using firebird 2.5, Jaybird 2.2.3 and JRE 1.7.0_55.
> >
> > When TCP/IP6 is installed (windows) the communications with the
> database
> > engine becomes very slow. It works but is 10 fold slower.
> > It does not matter if it's local or remote host.
> > We have our system running on independent database engines on over
> 200
> > computers, mostly on local host.
> >
> > When we remove completly TCP/IP 6 the problem is fixed.
> >
> > I have tried -Djava.net.preferIPv4Stack=true on the jvm but it does
> not
> > help.
>
> Which version of Windows do you use? I use Windows 7 and 8.1 with IP
> v6
> installed for testing and - as far as I am aware - I don't experience
> these problems. Could you quantify the times with and without IP v6?
>
> What happens if you specify the IP address instead of the hostname?
>
> Also what exactly becomes slower? Connect time, or does the entire
> connection itself become slow? I changed the hostname resolution
> between
> Jaybird 2.2.1 and 2.2.2, did this problem also occur before this
> change?
>
> Instead of looking at prefIPv4Stack, you might want to check the
> value
> of java.net.preferIPv6Addresses (default should be false, but this
> can
> be overridden on a system level).
>
> Mark
>
>
>