Difference between Internal IP Address and External IP Address

Question

Can anyone tell me what is difference between Internal IP Address and External IP Address? How to get both in any programming language like Java, C# or Adobe AIR?

For external IP address in Java, look here: http://stackoverflow.com/questions/2939218/getting-the-external-ip-address-in-java — MByD, Apr 04 '11 at 20:15

score 1 · Accepted Answer · answered Apr 04 '11 at 20:12

1

Internal IP address is the address from your network:

IPHostEntry heserver = Dns.GetHostEntry(Dns.GetHostName());
IPAddress curAdd = heserver.AddressList[0];
curAdd.ToString();

Your external IP address is the address from your ISP

string ip = new 
     System.Net.WebClient()
      .DownloadString(("http://www.whatismyip.com/automation/n09230945.asp"));

answered Apr 04 '11 at 20:12

SQLMason

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So how can we retrieve the External IP using C#? – Mudasir Bhutto Apr 04 '11 at 20:14
1

string hostName = Dns.GetHostName(); – SQLMason Apr 04 '11 at 20:34

score 1 · Answer 2 · answered Apr 04 '11 at 22:01

You can use the following code (in java) to get the local IP address:

public String getLocalIpAddress() {
     try {
         for (Enumeration en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();) {
             NetworkInterface ni = en.nextElement();
             for (Enumeration enumIpAddr = ni.getInetAddresses(); enumIpAddr.hasMoreElements();) {
                 InetAddress inetAddress = enumIpAddr.nextElement();
                 if (!inetAddress.isLoopbackAddress()) { //ignore 127.0.0.1
                     return inetAddress.getHostAddress().toString();
                 }
             }
         }
     } catch (SocketException ex) {
     }
     return null;
 }

Thanks a lot MByd. Please give me a code for geeting machine name in java too.... — Mudasir Bhutto, Apr 04 '11 at 22:06

Difference between Internal IP Address and External IP Address

2 Answers2

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