Problems with Java RMI when having multiple IPs (private IP and public IP)

[chaohua wang]

Hi Folks,

I have a RMI client, needs to add private IP adapter for cluster purpose. it communicates with RMI server at different machine.

IP config is this:

C:\>ipconfig

Windows IP Configuration


  Ethernet adapter Local Area Connection 2:

   Connection-specific DNS Suffix  . :
   Link-local IPv6 Address . . . . . : fe80::c969:3f78:3190:1f1c%11
   Autoconfiguration IPv4 Address. . : 169.254.31.28
   Subnet Mask . . . . . . . . . . . : 255.255.0.0
   Default Gateway . . . . . . . . . :

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix  . : io.fc.hp.com
   Link-local IPv6 Address . . . . . : fe80::1dbe:2ffd:f06a:9a56%10
   IPv4 Address. . . . . . . . . . . : 16.124.133.168
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 16.124.133.1

169.254.31.28 is a private IP. 16.124.133.168 is public IP.

Before I added this private IP. RMI client and Server communicate all right.

But After i added this private IP.


my client filed on a method call: servicesRef.getPaciVersions();

            Registry reg = LocateRegistry.getRegistry(connection.hostname, Integer.parseInt(connection.port),
                    factory);
            String providerName = findRegName(reg.list(), PROVIDER_NAME);
            ServiceNameProvider servicesRef = (ServiceNameProvider) reg.lookup(providerName);
             String[] paciVersions = servicesRef.getPaciVersions();

I debugged servicesRef object. its host is this private IP address (169.254.31.28). Before it was public IP,
so this call threw a IO exception.

I am not sure only why this host only has this private IP, no public IP. After I removed this private adapter, host has public IP.

my server RMI side. the code like this:

String name = "rmi://" + hostname 
		+  ":" + RmiPort + "/" + PROVIDER_NAME;

LocateRegistry.createRegistry(RmiPort,
				SSLSocketFactoryCreator.getInstance(), SSLSocketFactoryCreator.getInstance());

Registry reg = LocateRegistry.getRegistry(hostname , 
				RmiPort, SSLSocketFactoryCreator.getInstance());
 
PaciVersionService paciVesionService = new PaciVersionService(RmiPort);
reg.rebind(name, paciVesionService);

not sure why paciVesionService contains only private IP address. my code seems not do it.

Please help.

Thank you!

Chwang