1

Is there any router or database which can we access to put some access point or router MAC Address and get IP address?

Or i just think the mac address changes when a packet leave a router on the Internet?

user29111
  • 11

3 Answers3

4

In addition to tylerl's answer, remember that MAC addresses are only relevant on the local subnet.

MAC addresses belong to network cards, so each time a packet is forwarded by any host with a network card, the origin MAC address changes. That host can be a server, client, router, NAT gateway or what have you; anything which passes IP packets will almost by necessity cause the origin MAC address to change.

Community
  • 1
user
  • 29,910
3

No.

MAC addresses are resovled to IP addresses in real-time. No such database exists, and it would quickly become out-of-date if it did.

There are databases that associate your (wireless) router's MAC address to its physical location, which is how phones triangulate the location based on WiFi signals. But this is different from your IP address. It's also more useful for three-letter-agencies.

tylerl
  • 2,165
  • I heard that some Notational Security Agency have that DB which can find person from it's Network Device MAC Address , So it is impossible ? – user29111 Aug 05 '13 at 17:08
  • @user29111 - where did you hear that? If its on the internet, it must be true... – Keltari Aug 05 '13 at 17:12
  • @user29111 I wouldn't say something is "impossible" when talking about government agencies with budgets along the lines of the state budgets of small countries. That said, how would they map e.g. a library computer's NIC's MAC, sitting behind NAT and one or two layers of routers, to a particular individual? V1 GUIDs are mappable to NIC MACs, but if all you have is such a GUID, that still doesn't tell you who used the computer with that particular NIC at the time of GUID generation. – user Aug 05 '13 at 17:14
  • Edited to add geolocation note. – tylerl Aug 05 '13 at 17:33
0

MACs can be changed at any time. They are not set in stone, nor are the necessarily unique. You can write a script and randomize your MAC at random intervals.

Keltari
  • 73,243