How to obtain the MAC adress for your NIC

Metablade · 10-11-2005, 10:17 AM

Hello,
My question is:
How may I obtain my NIC card's Mac address using a command line in Linux?
Additionally Is this possible, and specifically what would I require I for? (aside from having the benefit of knowing what it is)
I assume that in attempting to connect to another computer, I'll need this in a file somewhere?

Or does Linux and another computer on the network automatically detect the MAC address?
I am a bit confused on why there would be a specific "need" to (if there is one) to know this.

Thank you.

aaa · 10-11-2005, 10:25 AM

To see it just run "ifconfig", and look under the nic you want (probably eth0). You don't need to know it, the computers just need to know each other's ip address.

Metablade · 10-11-2005, 10:30 AM

Thank you sir.

I ran "ifconfig" and I get a short display.
But I see nothing that says "eth0" (This should be my NIC card, yes?)
Would I be looking for a hexidecimal number?

Thanks again!

aaa · 10-11-2005, 11:17 AM

It might have a different name, the mac will look like 00:00:00:00:00:00, with various letters/numbers. The ip address is more important, like 192.168.1.1 for example.

Metablade · 10-11-2005, 11:32 AM

Hmmm..
Nothing like that on my system.
Here's what I get in response to ifconfig:
Link encap: Local Loopback
inet addr : 127.0.0.1 (Which I assume is home, Yes?)
Mask: 255.0.0.0
UP LOOPBACK RUNNING MTU: 16436 METRIC :1
RX packets :8 errors:0 dropped :0 overruns :0 frame :0
TX packets :8 errors :0 dropped :0 overruns :0 carrier :0
collisions :0 txqueuelen :0
RX bytes :560 (560.0b) TX bytes :560 (560.0b)

What does all of this mean?

-Thank you

aaa · 10-11-2005, 11:36 AM

That is lo device, which is something else. Try "ifconfig eth0" (guessing at the name again). It won't appear with just ifconfig if it is inactive.

Metablade · 10-11-2005, 12:01 PM

Bingo!
I think that's done it!
I receive:
HW 00

0:59:15:6C:07

I belive this is it.

Now, that said,
Why would I ever need to know this?
I seem to remember other sys ads referencing the MAC address, but had no idea why they needed it.

aaa · 10-11-2005, 01:15 PM

It's rarely needed. The other computer figures it out automatically if it needs it. It could be used to id a machine as each nic has a unique mac but you rarely need to worry about it. The important thing is the ip address, which is either also done automatically by dhcp, or set manually by you.

Metablade · 10-11-2005, 01:44 PM

Thank you once again!