To find out MAC address of any system remotely

Install Windump on your computer. Windump is a data sniffer.We will discuss more on data sniffers on other posts.

Start recording all the data packets sent and received by the computer.

Ping to remote computer or connect to the website or telnet to it.

Carefully analyze the captured datapackets and it shall contain MAC address of the remote system.

TIPS:

To avoid confusion try not to connect to other hosts or websites at the time of sniffing.
 There are other good data sniffing tools worth trying

Windump
Wiershark
Ethreal

etc are a few to name

MAC Address Spoofing

This is the art of changing the MAC address of the network adapter of a host. This is very helpful in misguiding the investigators in the event of a cyber crime.

There are two methods to spoof  the physical address of the host

Method 1:
start > run >  cmd > ipconfig/all

 Now you can analyze the data displayed on the screen to find out with which network adapter you are connecting to the WWW.Please take a note of it.

The next step is to download a tool named Etherchange.This is more of a command line application.
 Run this tool from the command prompt.( I do not believe in spoon feeding even that procedure to you so find it out  yourself )

Now read all the instructions shown in the screen and change the MAC address of your network adapter.


Method 2:

This method is a little complex when compared to Method 1.Here no softwares are there to assist us in spoofing.Also we are doing some simple registry edits.So be careful while dealing with registry of your PC.

Hey nothing to worry here... I was just kidding... so lets see Method 2

start > run > regedit

Now a screen will pop up... Now you are in the registry editor.

Browse the registry for HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002bE10318}

We can see many subkeys under the selection. All are 4 digit subkeys

Now manually determine which key belongs to the Ethernet adapter used to access data.For this  you can search for the term "DriverDesc" key till you find the needed one.
On the right hand pane create or edit the string key named "NetworkAddress". Be sure to make the data type to REG_SZ. The value of the string must be the new MAC address.

Now disable and enable the network adapter and run the ipconfig/all ... you will notice that the MAC address of your system has been spoofed.

This concludes the MAC spoofing

MAC Address or Media Access Control Address

MAC address is an unique identifier assigned to every network interface card or network adapters in any network.It is assigned by the manufacture.This is a 12 digit Hexa decimal number.The MAC address is actually the physical address of the network adapter.The unique nature of this ID makes it very helpful in computer forensics.We will discuss about this in detail in other posts.

So now we know what is a MAC address... But how can we find out the MAC address of our network adapter...?

start > run > cmd > type ipconfig/all

This will reveal the MAC address of your network adapter.

When ever a host connects to a network it is assigned with an IP.If we know the IP of the host in the network we can find its MAC address by analyzing the ARP table.We will discuss about the ARP table in another post.

To view the ARP table, type arp -a in the command prompt


TIPS :
For MAC address spoofing,Data traffic spoofing,Sniffing etc. MAC address of the default gateway is very useful.