Is it possible to track someone on the internet by converting thr MAC/Physical Address into Internet IP Address?
 
 or in other word, suppose I have Physical Address of someone  PC(ex- 00-19-5b-9c-21-34) and I want to know thr IP address, how it could be possible?

To expand slightly on heffnercj's post......

MAC to IP resolution is done using the ARP protocol.

ARP is non-routable so as heffnercj says "Any machines separated by a router will not see each other".

To track someone on the internet via their MAC address would therefore require some external mechanism ie software rn directly, as a worm, etc to feedback the IP address/MAC address relationship back to a central location. This approach would also need to ensure the information from devices that were behind firewalls or devices that were NATed could be captured as well.

Just imagine if Google ran some kind of script every time you accessed their site that did this correlation and held it in some kind of big database - EEEK!!. Scary thought and not beyond the realms of possibility. 

There are some ways of remotely determining a node's MAC address. Good ol' nbtstat comes to mind for windows machines. Today you are much less likely to receive a response to a NetBIOS query than say 5 years ago but this still works in many cases.

Jim

Just curious, how did you get their MAC and not their IP/DNS Hostname?

>because it was my own laptop MAC address which was stolen by someone

it means almost it is impossible to track any one from there MAC address.

But is it Possible to retrieve MAC address from someones IP address? if yes then pls let me know how to do that.

One remote possibility would be to wardrive and check for an active client with the same MAC, assuming that the interface was a wireless one. This would only work if

a) the laptop was power up
b) it has joined a wireless network
c) both of the above occur while your driving by

You could possibly set up a fake AP as part of your wardriving kit and hope it associates while your passing by. The chance of success is somewhere between long shot and fantasy however.

Jim

I think if you really needed to track a stolen laptop we need to forget the MAC address idea. The advice on this thread so far basically says in most cases you need to be on the same subnet as the 'physically compromised' machine to have a chance of tracking it.

There are other possibilities for tracking, but again the chances of success are slim. Is there any software on the laptop that 'phones home'? This might be for example an instant messenger account that's set to log in automatically. You could try creating a new account, adding your old account to your contacts and waiting to see if your account is logged in from elsewhere. The IM provider might give up the IP address but only to law enforcement agency.

The long and the short of it is that you're very unlikely to get your laptop back. Your best bet would be to ensure the theft has been reported to the police and that they have the serial number of the laptop in case it's recovered.

Regards,
Jim

well day by day it seems that internet security is getting tighter.Few years back we can easily get ip.host names withe use of cmd in windows,but nowdays its just noway. I just want to ask is there any way nowdays available for getting ip over global network??