for(int i=0;i<QNetworkInterface::allAddresses().size();i++)
    {
        Q_IPV6ADDR addr = QNetworkInterface::allAddresses().value(i).toIPv6Address();
//          addr contains 16 unsigned characters.This value is only valid if isIPv6Address() returns true.
        QString str;
         for (int i = 0; i < 16; ++i)
        {
             // process addr[ i ]
             str.append(addr [ i ]);
         }
        qDebug()<<str;
    }