How to detect my own MAC address from outside Internet (!) (NOT with ipconfig all)

  • Thread starter Thread starter Ken Philips
  • Start date Start date
K

Ken Philips

How can I find out my own MAC address FROM outside the local network?

Yes, I know, I could simply type

ipconfig /all

to find all my local adapters MAC addresses out.

However I am using a couple of Virtual Machines, Firewalls, Security tools
and routers and I guess at least one of them is modifying my original MAC address.

Similarly to servces like

www.whatismyip.com

which shows my own IP like it is seen from other users I could imagine
that there are services which show my MAC address as it is visible from
outside Internet.

Is there such a web page which displays my MAC address ?

Ken
 
Hi
Download this free util. http://www.softperfect.com/download/netscan.exe
It is one Exe file notching to install. Put it on your hard drive and drag a
link to a spot of your choice.
Run the program, in few seconds it will show you all the computers on the
network, MAC addresses, pings, shares, and more (make sure to look at the
Options Menu, and check all the options that would like to see).
Make sure that if you have Software Firewall that all the computers are on
the Trusted Zone.
Jack (MVP-Networking).
 
Does your Router not keep a list of connected machine MAC Address's. There
should be a page in the Admin functions that shows all connected MAC
Address's. Mine is called "DHCP Client List", which lists

IpAddress, Machine Name, MAC Address

You must be able to work it out from one of those.

Regards
 
How can I find out my own MAC address FROM outside the local network?

Yes, I know, I could simply type

ipconfig /all

to find all my local adapters MAC addresses out.

However I am using a couple of Virtual Machines, Firewalls, Security tools
and routers and I guess at least one of them is modifying my original MAC address.

Similarly to servces like

www.whatismyip.com

which shows my own IP like it is seen from other users I could imagine
that there are services which show my MAC address as it is visible from
outside Internet.

Is there such a web page which displays my MAC address ?

Ken
Click to expand...

Ken,

The MAC address is visible only to hosts on the same subnet. Outside the
subnet, all addressing is by IP address. Your MAC address simply isn't seen,
from the Internet.
<http://nitecruzr.blogspot.com/2005/10/mac-addresses.html>
http://nitecruzr.blogspot.com/2005/10/mac-addresses.html

--
Cheers,
Chuck, MS-MVP 2005-2007 [Windows - Networking]
http://nitecruzr.blogspot.com/
Paranoia is not a problem, when it's a normal response from experience.
My email is AT DOT
actual address pchuck mvps org.
 
How can I find out my own MAC address FROM outside the local
network?

Yes, I know, I could simply type

ipconfig /all

to find all my local adapters MAC addresses out.

However I am using a couple of Virtual Machines, Firewalls,
Security tools and routers and I guess at least one of them is
modifying my original MAC address.

Similarly to servces like

www.whatismyip.com

which shows my own IP like it is seen from other users I could
imagine that there are services which show my MAC address as it
is visible from outside Internet.

Is there such a web page which displays my MAC address ?

Ken
Click to expand...

Ken,

The MAC address is visible only to hosts on the same subnet.
Outside the subnet, all addressing is by IP address. Your MAC
address simply isn't seen, from the Internet.
Cheers,
Chuck, MS-MVP 2005-2007 [Windows - Networking]
Click to expand...


.... unless, of course, from a command prompt you use the:

nbtstat -A <ip address>

command which will coerce the target machine to report its MAC address
to the requester no matter which subnet it is on.

-- John
 
Chuck said:
How can I find out my own MAC address FROM outside the local network?

Yes, I know, I could simply type

ipconfig /all

to find all my local adapters MAC addresses out.

However I am using a couple of Virtual Machines, Firewalls, Security tools
and routers and I guess at least one of them is modifying my original MAC
address.

Similarly to servces like

www.whatismyip.com

which shows my own IP like it is seen from other users I could imagine
that there are services which show my MAC address as it is visible from
outside Internet.

Is there such a web page which displays my MAC address ?

Ken
Click to expand...

Ken,

The MAC address is visible only to hosts on the same subnet. Outside the
subnet, all addressing is by IP address. Your MAC address simply isn't
seen,
from the Internet.
<http://nitecruzr.blogspot.com/2005/10/mac-addresses.html>
http://nitecruzr.blogspot.com/2005/10/mac-addresses.html

--
Cheers,
Chuck, MS-MVP 2005-2007 [Windows - Networking]
http://nitecruzr.blogspot.com/
Paranoia is not a problem, when it's a normal response from experience.
My email is AT DOT
actual address pchuck mvps org.
Click to expand...
That is most interesting information Chuck...
Back when I was working for a living, I maintained an ethernet sniffer for
VMS which ran DECnet. Regardless of that fact, my sniffer detected every
computer on our segment of the
plant wide ethernet without regard to the network protocol that it was
using. I understood at the time that all ethernet adapters are expected to
broadcast their address at
regular intervals. My program placed the ethernet adapter on our VAX into
promiscuous mode (which causes the adapter to pass all packets to the
software). A VAX had a hard time keeping up; when I ported the program over
to an Alpha, things worked much better.

I suppose my point is that a program can be written which grabs all packets
which pass by without regard to whatever structure the IP believes it has.
By the way, DECnet and IP can coexist on the ethernet with no problems at
all.

Jim
 
Ken said:
How can I find out my own MAC address FROM outside the local network?
Click to expand...

The simple answer is that you cannot; it is almost meaningless beyond
the local network.

The more complex answer is that there may be an application you can
install on your PC to determine its own MAC addresses (one per IP
interface, both real and virtual) and to divulge this outside your
network, perhaps via a browser.

For example: http://swiftys.org.uk/macs
 
That is most interesting information Chuck...
Back when I was working for a living, I maintained an ethernet
sniffer for VMS which ran DECnet. Regardless of that fact, my
sniffer detected every computer on our segment of the
plant wide ethernet without regard to the network protocol that it
was using. I understood at the time that all ethernet adapters
are expected to broadcast their address at
regular intervals. My program placed the ethernet adapter on our
VAX into promiscuous mode (which causes the adapter to pass all
packets to the software). A VAX had a hard time keeping up; when
I ported the program over to an Alpha, things worked much better.

I suppose my point is that a program can be written which grabs
all packets which pass by without regard to whatever structure the
IP believes it has. By the way, DECnet and IP can coexist on the
ethernet with no problems at all.
Click to expand...

The MAC address exists at the lowest levels of the protocol stack and
is used as an outer wrapper to deliver a packet directly from one
device to another. If the destination device is a Router/Gateway, that
device then strips off the Ethernet wrapper and replaces it with one of
its own that sends the packet from that gateway to the next. All
traces of the original MAC address are lost at that point. A long time
ago, subnets were larger and broadcasts (like ARP) used to traverse
routers. Now, it is rare for a broadcast packet to survive past a
gateway.

Switches have now limited the amount of packets visible at an end
device to where promiscuous mode is almost moot. The only practical
way to find the MAC address of a device not on your subnet is to send a
packet to that device asking for it to reply with its MAC address.
That implies that a program or service is running on the target machine
that will willingly report that information. As part of the NetBT
service, Microsoft has provided that information by way of the
"nbtstat" program in which the target machine will report back its MAC
address among other info. Doing a remote registry query to the target
machine might be another way.

-- John
 
Back
Top