Reading MAC address

[satya sahu]

Hi all,
Is there any way to read MAC address of the ethernet card. My requirement is to enable & disable the ethernet card programatically. If java does not support then some C code and JNI will also solve my problem.
Please give me some solution.

[Stuart Gray]

In pure Java - impossible. Another language (C and Windows API?) and JNI are the way to go here without a doubt.

[Mark Wuest]

You can run an external program and parse the output.

In Linux, the program is "/sbin/ifconfig <interface>" - the number after HWaddr is the MAC address. e.g.:

 
$ /sbin/ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:0A:E6:CF:ED:B4
          inet addr:192.168.1.201  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:291390 errors:0 dropped:0 overruns:0 frame:0
          TX packets:319650 errors:0 dropped:1 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:83427788 (79.5 MiB)  TX bytes:192346097 (183.4 MiB)
          Interrupt:5 Base address:0xdc00

In the example above, 00:0A:E6:CF:ED:B4 is the MAC address.

In Windows, the command is "ipconfig /all" and the line with Physical Address in it has your MAC address. The line will look somewhat like this:

Physical Address. . . . . . . : 00:0A:E6:CF:ED:B4

You'd run it like this in Linux:

String[] execArgs = new String[2];
execArgs[0] = "/sbin/ifconfig";
execArgs[1] = "eth0"; // or the interface you want
 
Runtime runTime = Runtime.getRuntime()
Process theProcess = null;
try{
  theProcess = runTime.exec(execArgs);
} catch (Exception ex){ // there are 3 or 4 it can throw
  System.err.println("Darn thing won't run!");
  System.exit(1);
}
 
BufferedReader in = new BufferedReader(new InputStreamReader(theProcess.getInputStream()));

then read and parse 'in' for your answer.

Mark
[ June 04, 2005: Message edited by: Mark Wuest ]

[Steven Bell]

Keep in mind it is possible for a computer to have more than one MAC address.

[Stefan Wagner]

And possible to fake MAC-Adresses.