Netbeans cannot connect to internet (java.net.ConnectException: Network is unreachable)

(I'm not sure if this question belongs here or on superuser.com, but it's about IDE so...) So I installed Netbeans with installation bundle from netbeans.org and it can't connect to internet. It can't reload plugin catalog or upload files to FTP. While updating plugin catalog it gives me the error:

Unable to connect to the NetBeans because of java.net.ConnectException: Ne开发者_运维问答twork is unreachable

I'm using Crunchbang Linux statler (a debian-based distro) so I've also tried debian repositories and it actually worked (it could connect to internet), but the newest version there is 6.0 which is very old (at least for me).

Thank you for your answers.

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I had the same problem. Dual IP stack seems to cause this issue (see http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=560142).

Appending -J-Djava.net.preferIPv4Stack=true to netbeans_default_options variable in netbeans-6.9.1/etc/netbeans.conf has solved the problem for me.