I am trying to develop a system where there are different nodes that are run on different system or on different ports on the same system.

Now all the nodes create a Socket with a target IP as the IP of a special node known as a bootstrapping node. The nodes then create their own ServerSocket and start listening for connections.

The bootstrapping node maintains a list of Nodes and returns them on being queried.

Now what I need is the node must register its IP to the bootstrapping node. I tried using cli.getInetAddress() once the client connects to the ServerSocket of bootstrapping node but that didn't work.

  • I need the client to register its PPP IP if available;
  • Otherwise the LAN IP if available;
  • Otherwise it must register 127.0.0.1 assuming its the same computer.
  • Using the code:

    System.out.println(Inet4Address.getLocalHost().getHostAddress());
    
    System.out.println(InetAddress.getLocalHost().getHostAddress());
    

    My PPP Connection IP address is: 117.204.44.192 but the above returns me 192.168.1.2

    I am using the following code:

    Enumeration e = NetworkInterface.getNetworkInterfaces();
    while(e.hasMoreElements())
        NetworkInterface n = (NetworkInterface) e.nextElement();
        Enumeration ee = n.getInetAddresses();
        while (ee.hasMoreElements())
            InetAddress i = (InetAddress) ee.nextElement();
            System.out.println(i.getHostAddress());
    

    I am able to get all the IP addresses associated all NetworkInterfaces, but how do I distinguish them? This is the output I am getting:

    127.0.0.1
    192.168.1.2
    192.168.56.1
    117.204.44.19
                    Inside the loop if I add n.isPointToPoint() will that work??  My idea is to return "127.0.0.1" if no Point to Point network is found. Will that work??
                        – sasidhar
                    Feb 28 '12 at 18:48
                    @sasidhar : Please dont' post your genuine IP address. do write 117.xxx.xxx.xxx, for private IP that's okay.
                        – nIcE cOw
                    Feb 28 '12 at 19:01
                    @GagandeepBali Thanks for the advice but my IP is a dynamic IP and i get a new IP every time i disconnect and connect my internet. So shouldn't be a problem, I guess.
                        – sasidhar
                    Feb 29 '12 at 17:59
    try(final DatagramSocket socket = new DatagramSocket()){
      socket.connect(InetAddress.getByName("8.8.8.8"), 10002);
      ip = socket.getLocalAddress().getHostAddress();
    

    This way works well when there are multiple network interfaces. It always returns the preferred outbound IP. The destination 8.8.8.8 is not needed to be reachable.

    Connect on a UDP socket has the following effect: it sets the destination for Send/Recv, discards all packets from other addresses, and - which is what we use - transfers the socket into "connected" state, settings its appropriate fields. This includes checking the existence of the route to the destination according to the system's routing table and setting the local endpoint accordingly. The last part seems to be undocumented officially but it looks like an integral trait of Berkeley sockets API (a side effect of UDP "connected" state) that works reliably in both Windows and Linux across versions and distributions.

    So, this method will give the local address that would be used to connect to the specified remote host. There is no real connection established, hence the specified remote ip can be unreachable.

    Edit:

    As @macomgil says, for MacOS you can do this:

    Socket socket = new Socket();
    socket.connect(new InetSocketAddress("google.com", 80));
    System.out.println(socket.getLocalAddress());
            
                
                        improve this answer
                    @Jeef,  answer is updated. If it doesnt work on OsX,  then you need pick another way.
                        – Mr.Wang from Next Door
                    Mar 20 '18 at 10:50
                    Brilliant! FYI, when dealing with closed inner network, just replace 8.8.8.8 with something every host can reach
                        – Murphy Ng
                    Aug 3 '18 at 7:23
                        

    This could be a bit tricky in the most general case.

    On the face of it, InetAddress.getLocalHost() should give you the IP address of this host. The problem is that a host could have lots of network interfaces, and an interface could be bound to more than one IP address. And to top that, not all IP addresses will be reachable outside of your machine or your LAN. For example, they could be IP addresses for virtual network devices, private network IP addresses, and so on.

    What this means is that the IP address returned by InetAddress.getLocalHost() might not be the right one to use.

    How can you deal with this?

  • One approach is to use NetworkInterface.getNetworkInterfaces() to get all of the known network interfaces on the host, and then iterate over each NI's addresses.
  • Another approach is to (somehow) get the externally advertized FQDN for the host, and use InetAddress.getByName() to look up the primary IP address. (But how do you get it, and how do you deal with a DNS-based load balancer?)
  • A variation of the previous is to get the preferred FQDN from a config file or a command line parameter.
  • Another variation is to get the preferred IP address from a config file or a command line parameter.
  • In summary, InetAddress.getLocalHost() will typically work, but you may need to provide an alternative method for the cases where your code is run in an environment with "complicated" networking.

  • Any address in the range 127.xxx.xxx.xxx is a "loopback" address. It is only visible to "this" host.
  • Any address in the range 192.168.xxx.xxx is a private (aka site local) IP address. These are reserved for use within an organization. The same applies to 10.xxx.xxx.xxx addresses, and 172.16.xxx.xxx through 172.31.xxx.xxx.
  • Addresses in the range 169.254.xxx.xxx are link local IP addresses. These are reserved for use on a single network segment.
  • Addresses in the range 224.xxx.xxx.xxx through 239.xxx.xxx.xxx are multicast addresses.
  • The address 255.255.255.255 is the broadcast address.
  • Anything else should be a valid public point-to-point IPv4 address.
  • In fact, the InetAddress API provides methods for testing for loopback, link local, site local, multicast and broadcast addresses. You can use these to sort out which of the IP addresses you get back is most appropriate.

    improve this answer In case anyone is curious, getLocalHost essentially does a DNS lookup on the server's hostname. If it gets an IP address from that lookup then it searches through the interfaces available to see which interface has that IP address and it returns that interface. This means getLocalHost will tend to work in a "server" environment where the outgoing IP is the one that maps to the server's hostname. – Pace Jul 16 '14 at 7:30 On Ubuntu 14.04 this api returns 127.0.1.1 even though ifconfig only reports two interfaces, the one I want (the publicly accessible ip address), and loopback (127.0.0.1). Weird that it returns a different loopback alias. – ctpenrose Mar 24 '15 at 21:14 I'll add that if you use getLocalHost().getHostAddress() to publish something, you may see 0.0.0.0 when looking from a nother computer on the network. This is explained here This is what happened to me when i was using Gazebo across two computers – Peter Mitrano Jul 6 '15 at 23:50

    Posting here tested IP ambiguity workaround code from https://issues.apache.org/jira/browse/JCS-40 (InetAddress.getLocalHost() ambiguous on Linux systems):

    * Returns an <code>InetAddress</code> object encapsulating what is most likely the machine's LAN IP address. * This method is intended for use as a replacement of JDK method <code>InetAddress.getLocalHost</code>, because * that method is ambiguous on Linux systems. Linux systems enumerate the loopback network interface the same * way as regular LAN network interfaces, but the JDK <code>InetAddress.getLocalHost</code> method does not * specify the algorithm used to select the address returned under such circumstances, and will often return the * loopback address, which is not valid for network communication. Details * <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4665037">here</a>. * This method will scan all IP addresses on all network interfaces on the host machine to determine the IP address * most likely to be the machine's LAN address. If the machine has multiple IP addresses, this method will prefer * a site-local IP address (e.g. 192.168.x.x or 10.10.x.x, usually IPv4) if the machine has one (and will return the * first site-local address if the machine has more than one), but if the machine does not hold a site-local * address, this method will return simply the first non-loopback address found (IPv4 or IPv6). * If this method cannot find a non-loopback address using this selection algorithm, it will fall back to * calling and returning the result of JDK method <code>InetAddress.getLocalHost</code>. * @throws UnknownHostException If the LAN address of the machine cannot be found. private static InetAddress getLocalHostLANAddress() throws UnknownHostException { try { InetAddress candidateAddress = null; // Iterate all NICs (network interface cards)... for (Enumeration ifaces = NetworkInterface.getNetworkInterfaces(); ifaces.hasMoreElements();) { NetworkInterface iface = (NetworkInterface) ifaces.nextElement(); // Iterate all IP addresses assigned to each card... for (Enumeration inetAddrs = iface.getInetAddresses(); inetAddrs.hasMoreElements();) { InetAddress inetAddr = (InetAddress) inetAddrs.nextElement(); if (!inetAddr.isLoopbackAddress()) { if (inetAddr.isSiteLocalAddress()) { // Found non-loopback site-local address. Return it immediately... return inetAddr; else if (candidateAddress == null) { // Found non-loopback address, but not necessarily site-local. // Store it as a candidate to be returned if site-local address is not subsequently found... candidateAddress = inetAddr; // Note that we don't repeatedly assign non-loopback non-site-local addresses as candidates, // only the first. For subsequent iterations, candidate will be non-null. if (candidateAddress != null) { // We did not find a site-local address, but we found some other non-loopback address. // Server might have a non-site-local address assigned to its NIC (or it might be running // IPv6 which deprecates the "site-local" concept). // Return this non-loopback candidate address... return candidateAddress; // At this point, we did not find a non-loopback address. // Fall back to returning whatever InetAddress.getLocalHost() returns... InetAddress jdkSuppliedAddress = InetAddress.getLocalHost(); if (jdkSuppliedAddress == null) { throw new UnknownHostException("The JDK InetAddress.getLocalHost() method unexpectedly returned null."); return jdkSuppliedAddress; catch (Exception e) { UnknownHostException unknownHostException = new UnknownHostException("Failed to determine LAN address: " + e); unknownHostException.initCause(e); throw unknownHostException; improve this answer It must be noted that this still doesn't resolve ambuguity in case host has multiple similar nerwork interfaces. – Vadzim Dec 7 '13 at 8:53 the bellow answer is better - stackoverflow.com/questions/9481865/… gets the local ip address that is used as src for Default Gatway – Radu Toader Jun 27 '17 at 14:47 Why ip address is added with front slash ..? like /10.39.0.17 ..?, Is it always this way should be trimmed ..? – Kanagavelu Sugumar Sep 11 '17 at 5:08

    You can use java's InetAddress class for this purpose.

    InetAddress IP=InetAddress.getLocalHost();
    System.out.println("IP of my system is := "+IP.getHostAddress());
    

    Output for my system = IP of my system is := 10.100.98.228

    getHostAddress() returns

    Returns the IP address string in textual presentation.

    OR you can also do

    InetAddress IP=InetAddress.getLocalHost();
    System.out.println(IP.toString());
    

    Output = IP of my system is := RanRag-PC/10.100.98.228

    improve this answer Note that 10.x.x.x is a private address, indicating that your system is on a NAT network. It will appear as a different address when contacting the outside world. If you truly need the external IP address, you'll have to contact one of many sites which will echo back to you the IP address you're coming from. This may or may not be useful to you. Your system will almost surely not be reachable from the outside in any event. – Edward Falk Apr 19 '13 at 0:04

    When you are looking for your "local" address, you should note that each machine has not only a single network interface, and each interface could has its own local address. Which means your machine is always owning several "local" addresses.

    Different "local" addresses will be automatically chosen to use when you are connecting to different endpoints. For example, when you connect to google.com, you are using an "outside" local address; but when you connect to your localhost, your local address is always localhost itself, because localhost is just a loopback.

    Below is showing how to find out your local address when you are communicating with google.com:

    Socket socket = new Socket();
    socket.connect(new InetSocketAddress("google.com", 80));
    System.out.println(socket.getLocalAddress());
            
                
                        improve this answer
            try {
                url = new URL("http://bot.whatismyipaddress.com");
                in = new BufferedReader(new InputStreamReader(url.openStream()));
                ipAddress = in.readLine().trim();
                /* IF not connected to internet, then
                 * the above code will return one empty
                 * String, we can check it's length and
                 * if length is not greater than zero, 
                 * then we can go for LAN IP or Local IP
                 * or PRIVATE IP
                if (!(ipAddress.length() > 0)) {
                    try {
                        InetAddress ip = InetAddress.getLocalHost();
                        System.out.println((ip.getHostAddress()).trim());
                        ipAddress = (ip.getHostAddress()).trim();
                    } catch(Exception exp) {
                        ipAddress = "ERROR";
            } catch (Exception ex) {
                // This try will give the Private IP of the Host.
                try {
                    InetAddress ip = InetAddress.getLocalHost();
                    System.out.println((ip.getHostAddress()).trim());
                    ipAddress = (ip.getHostAddress()).trim();
                } catch(Exception exp) {
                    ipAddress = "ERROR";
                //ex.printStackTrace();
            System.out.println("IP Address: " + ipAddress);
    

    ACTUAL VERSION: This stopped working

    Hopefully this snippet might help you to achieve this :

    // Method to get the IP Address of the Host.
    private String getIP()
        // This try will give the Public IP Address of the Host.
            URL url = new URL("http://automation.whatismyip.com/n09230945.asp");
            BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
            String ipAddress = new String();
            ipAddress = (in.readLine()).trim();
            /* IF not connected to internet, then
             * the above code will return one empty
             * String, we can check it's length and
             * if length is not greater than zero, 
             * then we can go for LAN IP or Local IP
             * or PRIVATE IP
            if (!(ipAddress.length() > 0))
                    InetAddress ip = InetAddress.getLocalHost();
                    System.out.println((ip.getHostAddress()).trim());
                    return ((ip.getHostAddress()).trim());
                catch(Exception ex)
                    return "ERROR";
            System.out.println("IP Address is : " + ipAddress);
            return (ipAddress);
        catch(Exception e)
            // This try will give the Private IP of the Host.
                InetAddress ip = InetAddress.getLocalHost();
                System.out.println((ip.getHostAddress()).trim());
                return ((ip.getHostAddress()).trim());
            catch(Exception ex)
                return "ERROR";
            
                
                        improve this answer
                    The solution would work, hopefully if i am always connected to the internet, but i am not guaranteed that. Besides, when the system is not connected to the internet and then I need to return the LAN IP address of the system if any, otherwise the localhost. So not a feasible option for me. Any other way??
                        – sasidhar
                    Feb 28 '12 at 17:34
                    @sasidhar : When you are connected to the Internet, only then you be having your public IP I guess, if you are not connected then this method will give you, your local IP or LAN IP, and for the last condition as specified by you you can return "127.0.0.1", instead of returning Error.
                        – nIcE cOw
                    Feb 28 '12 at 17:40
                    I like your approach but that link seems not to work anymore!! Can I put a controller on my own system to work instead of that external link and so be more reliable???
                        – azerafati
                    Aug 27 '14 at 12:23
                    @Bludream: Thankyou so much, for bringing this to my knowledge, that the link is not working anymore. I have updated the post, with some new inputs. Hopefully it works for your usercase. Regarding your question, I really don't know, how to setup a controller on your own system to make it work. So I won't be able to give insight on this topic, MY BAD. Thanks again and KEEP SMILING :-)
                        – nIcE cOw
                    Aug 27 '14 at 15:48
                    As much as this is a cool solution, It is extremely unreliable. If you were to block the main thread (lets say) and for whatever reason whatismyip.com was down for some length of time, your app would also be down :(. Or it will return garbage data and cause unexpected behavior. Also, this returns the outter most IP address detectable by whatismyip.com, not necessarily the ip address of the machine you're using.
                        – Decoded
                    Mar 13 '17 at 22:39
      def getIpAddress: String = {
        val enumeration = NetworkInterface.getNetworkInterfaces.asScala.toSeq
        val ipAddresses = enumeration.flatMap(p =>
          p.getInetAddresses.asScala.toSeq
        val address = ipAddresses.find { address =>
          val host = address.getHostAddress
          host.contains(".") && !address.isLoopbackAddress
        }.getOrElse(InetAddress.getLocalHost)
        address.getHostAddress
            
                
                        improve this answer
    
      InetAddress iAddress = InetAddress.getLocalHost();
      String currentIp = iAddress.getHostAddress();
      System.out.println("Current IP address : " +currentIp); //gives only host address
            
                
                        improve this answer
                        
    private static InetAddress getLocalAddress(){
            try {
                Enumeration<NetworkInterface> b = NetworkInterface.getNetworkInterfaces();
                while( b.hasMoreElements()){
                    for ( InterfaceAddress f : b.nextElement().getInterfaceAddresses())
                        if ( f.getAddress().isSiteLocalAddress())
                            return f.getAddress();
            } catch (SocketException e) {
                e.printStackTrace();
            return null;
            
                
                        improve this answer
            
                
                        improve this answer
                        

    This is a working example of the ACCEPTED answer above! This NetIdentity class will store both the internal host ip, as well as the local loopback. If you're on a DNS based server, as mentioned above, you may need to add some more checks, or possible go the Configuration File Route.

    import java.net.InetAddress;
    import java.net.NetworkInterface;
    import java.net.SocketException;
    import java.net.UnknownHostException;
    import java.util.Enumeration;
     * Class that allows a device to identify itself on the INTRANET.
     * @author Decoded4620 2016
    public class NetIdentity {
        private String loopbackHost = "";
        private String host = "";
        private String loopbackIp = "";
        private String ip = "";
        public NetIdentity(){
                Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
                while(interfaces.hasMoreElements()){
                    NetworkInterface i = interfaces.nextElement();
                    if(i != null){
                        Enumeration<InetAddress> addresses = i.getInetAddresses();
                        System.out.println(i.getDisplayName());
                        while(addresses.hasMoreElements()){
                            InetAddress address = addresses.nextElement();
                            String hostAddr = address.getHostAddress();
                            // local loopback
                            if(hostAddr.indexOf("127.") == 0 ){
                                this.loopbackIp = address.getHostAddress();
                                this.loopbackHost = address.getHostName();
                            // internal ip addresses (behind this router)
                            if( hostAddr.indexOf("192.168") == 0 || 
                                    hostAddr.indexOf("10.") == 0 || 
                                    hostAddr.indexOf("172.16") == 0 ){
                                this.host = address.getHostName();
                                this.ip = address.getHostAddress();
                            System.out.println("\t\t-" + address.getHostName() + ":" + address.getHostAddress() + " - "+ address.getAddress());
            catch(SocketException e){
                InetAddress loopbackIpAddress = InetAddress.getLocalHost();
                this.loopbackIp = loopbackIpAddress.getHostName();
                System.out.println("LOCALHOST: " + loopbackIp);
            catch(UnknownHostException e){
                System.err.println("ERR: " + e.toString());
        public String getLoopbackHost(){
            return loopbackHost;
        public String getHost(){
            return host;
        public String getIp(){
            return ip;
        public String getLoopbackIp(){
            return loopbackIp;
    

    When I run this code I actually get a print out like this:

        Software Loopback Interface 1
            -127.0.0.1:127.0.0.1 - [B@19e1023e
            -0:0:0:0:0:0:0:1:0:0:0:0:0:0:0:1 - [B@7cef4e59
    Broadcom 802.11ac Network Adapter
            -VIKING.yourisp.com:192.168.1.142 - [B@64b8f8f4
            -fe80:0:0:0:81fa:31d:21c9:85cd%wlan0:fe80:0:0:0:81fa:31d:21c9:85cd%wlan0 - [B@2db0f6b2
    Microsoft Kernel Debug Network Adapter
    Intel Edison USB RNDIS Device
    Driver for user-mode network applications
    Cisco Systems VPN Adapter for 64-bit Windows
    VirtualBox Host-Only Ethernet Adapter
            -VIKING:192.168.56.1 - [B@3cd1f1c8
            -VIKING:fe80:0:0:0:d599:3cf0:5462:cb7%eth4 - [B@3a4afd8d
    LogMeIn Hamachi Virtual Ethernet Adapter
            -VIKING:25.113.118.39 - [B@1996cd68
            -VIKING:2620:9b:0:0:0:0:1971:7627 - [B@3339ad8e
            -VIKING:fe80:0:0:0:51bf:994d:4656:8486%eth5 - [B@555590
    Bluetooth Device (Personal Area Network)
            -fe80:0:0:0:4c56:8009:2bca:e16b%eth6:fe80:0:0:0:4c56:8009:2bca:e16b%eth6 - [B@3c679bde
    Bluetooth Device (RFCOMM Protocol TDI)
    Intel(R) Ethernet Connection (2) I218-V
            -fe80:0:0:0:4093:d169:536c:7c7c%eth7:fe80:0:0:0:4093:d169:536c:7c7c%eth7 - [B@16b4a017
    Microsoft Wi-Fi Direct Virtual Adapter
            -fe80:0:0:0:103e:cdf0:c0ac:1751%wlan1:fe80:0:0:0:103e:cdf0:c0ac:1751%wlan1 - [B@8807e25
    VirtualBox Host-Only Ethernet Adapter-HHD Software NDIS 6.0 Filter Driver-0000
    VirtualBox Host-Only Ethernet Adapter-WFP Native MAC Layer LightWeight Filter-0000
    VirtualBox Host-Only Ethernet Adapter-HHD Software NDIS 6.0 Filter Driver-0001
    VirtualBox Host-Only Ethernet Adapter-HHD Software NDIS 6.0 Filter Driver-0002
    VirtualBox Host-Only Ethernet Adapter-VirtualBox NDIS Light-Weight Filter-0000
    VirtualBox Host-Only Ethernet Adapter-HHD Software NDIS 6.0 Filter Driver-0003
    VirtualBox Host-Only Ethernet Adapter-QoS Packet Scheduler-0000
    VirtualBox Host-Only Ethernet Adapter-HHD Software NDIS 6.0 Filter Driver-0004
    VirtualBox Host-Only Ethernet Adapter-WFP 802.3 MAC Layer LightWeight Filter-0000
    VirtualBox Host-Only Ethernet Adapter-HHD Software NDIS 6.0 Filter Driver-0005
    Intel(R) Ethernet Connection (2) I218-V-HHD Software NDIS 6.0 Filter Driver-0000
    Intel(R) Ethernet Connection (2) I218-V-WFP Native MAC Layer LightWeight Filter-0000
    Intel(R) Ethernet Connection (2) I218-V-HHD Software NDIS 6.0 Filter Driver-0001
    Intel(R) Ethernet Connection (2) I218-V-Shrew Soft Lightweight Filter-0000
    Intel(R) Ethernet Connection (2) I218-V-HHD Software NDIS 6.0 Filter Driver-0002
    Intel(R) Ethernet Connection (2) I218-V-VirtualBox NDIS Light-Weight Filter-0000
    Intel(R) Ethernet Connection (2) I218-V-HHD Software NDIS 6.0 Filter Driver-0003
    Intel(R) Ethernet Connection (2) I218-V-QoS Packet Scheduler-0000
    Intel(R) Ethernet Connection (2) I218-V-HHD Software NDIS 6.0 Filter Driver-0004
    Intel(R) Ethernet Connection (2) I218-V-WFP 802.3 MAC Layer LightWeight Filter-0000
    Intel(R) Ethernet Connection (2) I218-V-HHD Software NDIS 6.0 Filter Driver-0005
    Broadcom 802.11ac Network Adapter-WFP Native MAC Layer LightWeight Filter-0000
    Broadcom 802.11ac Network Adapter-Virtual WiFi Filter Driver-0000
    Broadcom 802.11ac Network Adapter-Native WiFi Filter Driver-0000
    Broadcom 802.11ac Network Adapter-HHD Software NDIS 6.0 Filter Driver-0003
    Broadcom 802.11ac Network Adapter-Shrew Soft Lightweight Filter-0000
    Broadcom 802.11ac Network Adapter-HHD Software NDIS 6.0 Filter Driver-0004
    Broadcom 802.11ac Network Adapter-VirtualBox NDIS Light-Weight Filter-0000
    Broadcom 802.11ac Network Adapter-HHD Software NDIS 6.0 Filter Driver-0005
    Broadcom 802.11ac Network Adapter-QoS Packet Scheduler-0000
    Broadcom 802.11ac Network Adapter-HHD Software NDIS 6.0 Filter Driver-0006
    Broadcom 802.11ac Network Adapter-WFP 802.3 MAC Layer LightWeight Filter-0000
    Broadcom 802.11ac Network Adapter-HHD Software NDIS 6.0 Filter Driver-0007
    Microsoft Wi-Fi Direct Virtual Adapter-WFP Native MAC Layer LightWeight Filter-0000
    Microsoft Wi-Fi Direct Virtual Adapter-Native WiFi Filter Driver-0000
    Microsoft Wi-Fi Direct Virtual Adapter-HHD Software NDIS 6.0 Filter Driver-0002
    Microsoft Wi-Fi Direct Virtual Adapter-Shrew Soft Lightweight Filter-0000
    Microsoft Wi-Fi Direct Virtual Adapter-HHD Software NDIS 6.0 Filter Driver-0003
    Microsoft Wi-Fi Direct Virtual Adapter-VirtualBox NDIS Light-Weight Filter-0000
    Microsoft Wi-Fi Direct Virtual Adapter-HHD Software NDIS 6.0 Filter Driver-0004
    Microsoft Wi-Fi Direct Virtual Adapter-QoS Packet Scheduler-0000
    Microsoft Wi-Fi Direct Virtual Adapter-HHD Software NDIS 6.0 Filter Driver-0005
    Microsoft Wi-Fi Direct Virtual Adapter-WFP 802.3 MAC Layer LightWeight Filter-0000
    Microsoft Wi-Fi Direct Virtual Adapter-HHD Software NDIS 6.0 Filter Driver-0006
    

    For my use I'm setting up a Upnp Server, it helped to understand the 'pattern' that i was looking for. Some of the objects returned are Ethernet Adapters, Network Adapters, Virtual Network Adapters, Drivers, and VPN Client Adapters. Not everything has an Address either. So you'll want to skip out on interface objects that don't.

    You can also add this to the loop for the current NetworkInterface i

    while(interfaces.hasMoreElements()){
        Enumeration<InetAddress> addresses = i.getInetAddresses();
        System.out.println(i.getDisplayName());
        System.out.println("\t- name:" + i.getName());
        System.out.println("\t- idx:" + i.getIndex());
        System.out.println("\t- max trans unit (MTU):" + i.getMTU());
        System.out.println("\t- is loopback:" + i.isLoopback());
        System.out.println("\t- is PPP:" + i.isPointToPoint());
        System.out.println("\t- isUp:" + i.isUp());
        System.out.println("\t- isVirtual:" + i.isVirtual());
        System.out.println("\t- supportsMulticast:" + i.supportsMulticast());
    

    And You'll see information in your output much like this:

    Software Loopback Interface 1
        - name:lo
        - idx:1
        - max trans unit (MTU):-1
        - is loopback:true
        - is PPP:false
        - isUp:true
        - isVirtual:false
        - supportsMulticast:true
            -ADRESS: [127.0.0.1(VIKING-192.168.56.1)]127.0.0.1:127.0.0.1 - [B@19e1023e
            -ADRESS: [0:0:0:0:0:0:0:1(VIKING-192.168.56.1)]0:0:0:0:0:0:0:1:0:0:0:0:0:0:0:1 - [B@7cef4e59
    Broadcom 802.11ac Network Adapter
        - name:wlan0
        - idx:2
        - max trans unit (MTU):1500
        - is loopback:false
        - is PPP:false
        - isUp:true
        - isVirtual:false
        - supportsMulticast:true
            -ADRESS: [VIKING.monkeybrains.net(VIKING-192.168.56.1)]VIKING.monkeybrains.net:192.168.1.142 - [B@64b8f8f4
            -ADRESS: [fe80:0:0:0:81fa:31d:21c9:85cd%wlan0(VIKING-192.168.56.1)]fe80:0:0:0:81fa:31d:21c9:85cd%wlan0:fe80:0:0:0:81fa:31d:21c9:85cd%wlan0 - [B@2db0f6b2
    Microsoft Kernel Debug Network Adapter
        - name:eth0
        - idx:3
        - max trans unit (MTU):-1
        - is loopback:false
        - is PPP:false
        - isUp:false
        - isVirtual:false
        - supportsMulticast:true
            
                
                        improve this answer
    try {
      InetAddress addr = InetAddress.getLocalHost();            
      System.out.println(addr.getHostAddress());
    } catch (UnknownHostException e) {
            
                
                        improve this answer
                    My PPP Connection Ip address is: 117.204.44.192 But the above returns me 192.168.1.2
                        – sasidhar
                    Feb 28 '12 at 12:54
                    You need to crawl all the InetAddress instances available and figure out which is the proper one.
                        – Decoded
                    Mar 13 '17 at 22:40
                        
    import java.net.InetAddress;
    import java.net.NetworkInterface;
    import java.util.Enumeration;
    public class IpAddress {
    NetworkInterface ifcfg;
    Enumeration<InetAddress> addresses;
    String address;
    public String getIpAddress(String host) {
        try {
            ifcfg = NetworkInterface.getByName(host);
            addresses = ifcfg.getInetAddresses();
            while (addresses.hasMoreElements()) {
                address = addresses.nextElement().toString();
                address = address.replace("/", "");
        } catch (Exception e) {
            e.printStackTrace();
        return ifcfg.toString();
            
                
                        improve this answer
                        

    A rather simplistic approach that seems to be working...

    String getPublicIPv4() throws UnknownHostException, SocketException{
        Enumeration<NetworkInterface> e = NetworkInterface.getNetworkInterfaces();
        String ipToReturn = null;
        while(e.hasMoreElements())
            NetworkInterface n = (NetworkInterface) e.nextElement();
            Enumeration<InetAddress> ee = n.getInetAddresses();
            while (ee.hasMoreElements())
                InetAddress i = (InetAddress) ee.nextElement();
                String currentAddress = i.getHostAddress();
                logger.trace("IP address "+currentAddress+ " found");
                if(!i.isSiteLocalAddress()&&!i.isLoopbackAddress() && validate(currentAddress)){
                    ipToReturn = currentAddress;    
                }else{
                    System.out.println("Address not validated as public IPv4");
        return ipToReturn;
    private static final Pattern IPv4RegexPattern = Pattern.compile(
            "^(([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\.){3}([01]?\\d\\d?|2[0-4]\\d|25[0-5])$");
    public static boolean validate(final String ip) {
        return IPv4RegexPattern.matcher(ip).matches();
            
                
                        improve this answer
    
    try {
        System.out.println(InetAddress.getLocalHost().getHostAddress());
    } catch (UnknownHostException e) {
        e.printStackTrace();
            
                
                        improve this answer
                        

    Usually when i try to find my public IP Address like cmyip.com or www.iplocation.net, i use this way:

    public static String myPublicIp() {
        /*nslookup myip.opendns.com resolver1.opendns.com*/
        String ipAdressDns  = "";
        try {
            String command = "nslookup myip.opendns.com resolver1.opendns.com";
            Process proc = Runtime.getRuntime().exec(command);
            BufferedReader stdInput = new BufferedReader(new InputStreamReader(proc.getInputStream()));
            String s;
            while ((s = stdInput.readLine()) != null) {
                ipAdressDns  += s + "\n";
        } catch (IOException e) {
            e.printStackTrace();
        return ipAdressDns ;
            
                
                        improve this answer
        try {
            Enumeration<NetworkInterface> networkInterfaces = NetworkInterface.getNetworkInterfaces();
            while (networkInterfaces.hasMoreElements()) {
                NetworkInterface networkInterface = networkInterfaces.nextElement();
                byte[] hardwareAddress = networkInterface.getHardwareAddress();
                if (null == hardwareAddress || 0 == hardwareAddress.length || (0 == hardwareAddress[0] && 0 == hardwareAddress[1] && 0 == hardwareAddress[2])) continue;
                Enumeration<InetAddress> inetAddresses = networkInterface.getInetAddresses();
                if (inetAddresses.hasMoreElements()) ipAddress = inetAddresses.nextElement().toString();
                break;
        } catch (SocketException e) {
            e.printStackTrace();
        return ipAddress;
            
                
                        improve this answer