Network unreachable in java only

[Kjella]

After the last apt-get update/dist-upgrade, my java applications have stopped working. I can browse, play online games, chat and whatever else applications run fine, but my java applications all error out like this:

Error while sending packet to 70.83.141.197:38954: java.io.IOException: Network is unreachable

I have not changed any settings, firewalls or anything else related to the network in this timeperiod. Everything looks normal to me, I can for example without problems complete a traceroute:

kjellrs@arrakis:~$ sudo tracert 70.83.141.197
[sudo] password for kjellrs:
traceroute to 70.83.141.197 (70.83.141.197), 30 hops max, 60 byte packets
 1 192.168.0.1 (192.168.0.1) 0.130 ms 0.131 ms *
 2 * * *
 3 * * *
 4 * * *
 5 * * *
 6 * ti3003c310-ae6-0.ti.telenor.net (146.172.100.37) 14.940 ms 14.950 ms
 7 ti3004b300-ae1-0.ti.telenor.net (146.172.105.34) 14.965 ms 15.007 ms 14.973 ms
 8 212.73.252.1 (212.73.252.1) 19.675 ms * 20.050 ms
 9 * * *
10 * * *
11 * * *
12 * * *
13 * ae-1-51.edge4.Amsterdam1.Level3.net (4.69.139.138) 37.923 ms 37.764 ms
14 acr1-so-3-0-0.Amsterdamamx.savvis.net (208.174.49.1) 38.719 ms 38.741 ms 38.763 ms
15 dcr1-so-1-0-0.amsterdamamx.savvis.net (204.70.193.146) 38.619 ms 41.915 ms 41.998 ms
16 cr2-pos-0-15-3-0.Washington.savvis.net (204.70.192.125) 135.875 ms 135.896 ms 135.775 ms
17 cpr2-ge-5-0.virginiaequinix.savvis.net (204.70.193.101) 130.292 ms 130.367 ms 130.390 ms
18 216.113.122.85 (216.113.122.85) 159.882 ms 159.961 ms *
19 * * *
20 * * *
21 * * *
22 * * *
23 * modemcable197.141-83-70.mc.videotron.ca (70.83.141.197) 166.913 ms 171.963 ms

Is there possibly some sort of policy that could be blocking java? I have made absolutely no such policy configuration, but this is an upgrade from jaunty to karmic...

ProblemType: Bug
Architecture: i386
Date: Sat Nov 21 10:46:20 2009
DistroRelease: Ubuntu 9.10
NonfreeKernelModules: nvidia
Package: sun-java6-bin 6-15-1
ProcEnviron:
 LANGUAGE=
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-14.48-generic
SourcePackage: sun-java6
Uname: Linux 2.6.31-14-generic i686
XsessionErrors: (polkit-gnome-authentication-agent-1:2532): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed

[Heikki Henriksen (heikkih)]

This is a symptom of a bug in sun's java6 regarding ipv6.

Try
$ /sbin/sysctl net.ipv6.bindv6only

If this value is 1 you need to disable the setting:

$ sudo /sbin/sysctl net.ipv6.bindv6only=0

For a persistent fix:
Check /etc/sysctl.conf and /etc/sysctl.d/* for this setting and restart procfs after changing it.

If this was your problem, you should have networking back :)

Cheers.

[guysoft (guysoft)]

Hello there,
Debian here, had the same problem in a file /etc/sysctl.d/bindv6only.conf
The above fixed it

[Matthias Klose (doko)]

fixed in 6b18~pre3-0ubuntu1; the debian report has more details

[estranged1977 (estranged1977)]

Hi everybody, I was trying to solve this for about a month, and the truth is that was something very stupid, I have 5 pc all with ubuntu and 3 of them were working good without any problem connecting to a firebird server with java, the problem was with the others two, first I was thinking in the version of ubuntu with problems in java ...but the problem was only that the file /etc/hosts was with 127.0.1.1 with a diferent name of the name provided at /etc/hostname, that was all...my /etc/hosts was 127.0.0.1 localhost then 127.0.1.1 myserver.mydomain myserver and my file /etc/hostname was myserver2 so I just edited /etc/hosts and wrote 127.0.0.1 localhost and 127.0.1.1 myserver2 nothing else...and IT WORKS...

I don`t know what is the tech reason for this but I fixed and now im going to drink a full bottle of tequila to celebrate...cheers...

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.