On Linux RH dual stack machine InetAddress.getAllByName(hostname) is giving only IPv4 address. I tested with Linux RH7.1 with kernel 2.4.1.


How to reproduce it:
-------------------

1. Take the below pasted code and execute ..

import java.net.*;
import java.io.*;

public class GetIP {


   public static void main(String[] arg)
   {
       try {

         InetAddress[] iadr = InetAddress.getAllByName(arg[0]);
        System.out.println("iadr length " + iadr.length);

        System.out.println("host name " + arg[0]);
        InetAddress iadrnic = InetAddress.getByName(arg[0]);
        System.out.println("AFter getting iadr ");

        NetworkInterface niface = NetworkInterface.getByAddr(iadrnic);

        System.out.println("AFter getting niface");

        System.out.println("network interface " + niface);

         for(int i=0; i< iadr.length; i++)
         {
          System.out.println("ip address : " + iadr[i].getHostAddress());
          System.out.println(" Host Name :" + iadr[i].getHostName());
          //System.out.println("family " + iadr[i].getFamily());
          System.out.println("Host aadd byte arr " + iadr[i].getAddress());
          if(iadr[i] instanceof Inet4Address)
                System.out.println("v4 address");
          if(iadr[i] instanceof Inet6Address)
                System.out.println("v6 address ");

          if(!iadr[i].isMCOrgLocal()) {
              System.out.println("NOt org local scope");
           }
         // InetAddress[] iadrtest = InetAddress.getAllByName(iadr[i].getHostName());
          InetAddress iadrtest = InetAddress.getByName(iadr[i].getHostName());
          System.out.println("working....");
         }

      } catch(Exception exp) {
         System.out.println("exp mesg " + exp.getMessage());
         exp.printStackTrace();
      }
   } // End of main

}


Execution output:
==================

java GetIP isolinear
iadr length 1
host name isolinear
AFter getting iadr
AFter getting niface
network interface name:lo (lo) index: 1 addresses:
/0:0:0:0:0:0:0:1;
/127.0.0.1;

ip address : 127.0.0.1
 Host Name :isolinear
Host aadd byte arr [B@f62373
v4 address
NOt org local scope
working....

and ifconfig -a on same machine shows both the addresses.
======================
eth0 Link encap:Ethernet HWaddr 00:01:03:1A:7B:EF
          inet addr:10.7.130.13 Bcast:10.7.130.255 Mask:255.255.255.0
          inet6 addr: fe80::201:3ff:fe1a:7bef/10 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:1829967 errors:0 dropped:0 overruns:81 frame:0
          TX packets:2861824 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          RX bytes:355952814 (339.4 Mb) TX bytes:3302627646 (3149.6 Mb)
          Interrupt:11 Base address:0xdc00