Quick question> Mac address

Ice Rich · 27 Apr 2007 at 16:01

Hi all,

Just making notes of all my important stuff. Is your MAC address (as in internet terms) permanent? Is does not change like an ip does it?

Thanks

tedaC · 27 Apr 2007 at 16:03

Mac address is unique and permanent to the piece of hardware you are using yes

WotDa · 27 Apr 2007 at 16:06

tedaC said:
Mac address is unique and permanent to the piece of hardware you are using yes

It's only unique until it gets spoofed.

Ice Rich · 27 Apr 2007 at 16:25

WotDa said:
It's only unique until it gets spoofed.

spoofed, what does that mean?

sniffy · 27 Apr 2007 at 16:32

Spoofed means it can be copied.

You can trick a PC into thinking your MAC address is the gateway's MAC address (therefore the MAC is not longer unique). This essentially means you can access any data going out from that port.

Someone correct me if I'm wrong please

Ice Rich · 27 Apr 2007 at 16:38

Is there anyway to find out if you MAC has been copied?

sniffy · 27 Apr 2007 at 16:47

I know very little about networks so I can't really say for sure. I would imagine it's possible though. Either by using special software or doing it yourself manually.

Sp00n · 27 Apr 2007 at 16:48

Ice Rich said:
Is there anyway to find out if you MAC has been copied?

Not unless you want to check every piece of computer network hardware ever, no.

leaskovski · 27 Apr 2007 at 16:49

tedaC said:
Mac address is unique and permanent to the piece of hardware you are using yes

sniffy · 27 Apr 2007 at 16:50

leaskovski said:
<Goes and alters MAC in bios settings>

I'm not sure but I think it only applies to networking hardware such as network cards.

flump · 27 Apr 2007 at 16:53

Basically no, it's not, although the chances of finding a twin are rare!

If you run VM ware or the like you can have multiple virtual NIC's with the same MAC. Some onboard NIC might allow you to change this in the bios, as suggested above.

leaskovski · 27 Apr 2007 at 16:55

sniffy said:
I'm not sure but I think it only applies to networking hardware such as network cards.

Ah, i now i get it. I didn't realise he was talking about the kit you connect to. Hmm, if you are connected via a router then your mac address on the interclick is the mac of the router is it not? :confused:

sniffy · 27 Apr 2007 at 16:59

leaskovski said:
Ah, i now i get it. I didn't realise he was talking about the kit you connect to. Hmm, if you are connected via a router then your mac address on the interclick is the mac of the router is it not?

Good question. I have no idea what the answer is.

Dingleberry88 · 27 Apr 2007 at 17:01

leaskovski said:
Ah, i now i get it. I didn't realise he was talking about the kit you connect to. Hmm, if you are connected via a router then your mac address on the interclick is the mac of the router is it not?

Think so.

Sp00n · 27 Apr 2007 at 17:26

If it uses NAT then yes, it is.

Dano · 27 Apr 2007 at 17:38

tedaC said:
Mac address is unique and permanent to the piece of hardware you are using yes

Not if you get two cards with the same MAC, spent several frustrating hours before I knew anything about networking trying to get them to speak to each other, a friend came round who knew what he was doing and discovered it, he was somewhat suprised

Psyk · 27 Apr 2007 at 17:44

leaskovski said:
Ah, i now i get it. I didn't realise he was talking about the kit you connect to. Hmm, if you are connected via a router then your mac address on the interclick is the mac of the router is it not?

interclick = internet? :confused:

Anyway your mac address (even your router's) is not publically known to other people on the internet. Mac addresses are only needed for the local network, so the only party other than yourself that has access to your router's mac address is your isp. It's purely used for that single link between you and your isp. In fact I'm not even sure some types of internet connection even have the concept of a mac address, so it wouldn't be used at all outside of your own network.

With a cable modem I imagine the only device that has knowledge of your router's mac address is the cable modem itself.

sniffy · 27 Apr 2007 at 17:46

Dano said:
Not if you get two cards with the same MAC, spent several frustrating hours before I knew anything about networking trying to get them to speak to each other, a friend came round who knew what he was doing and discovered it, he was somewhat suprised

You'd have a better chance winning the lottery, considering there are 2 to the power of 48 (or 281,474,976,710,656) possible MAC addresses. I imagine it was set-up incorrect and you somehow managed to assign a locally administered address.

Psyk · 27 Apr 2007 at 17:48

sniffy said:
You'd have a better chance winning the lottery, considering there are 2 to the power of 48 (or 281,474,976,710,656) possible MAC addresses. I imagine it was set-up incorrect and you somehow managed to assign a locally administered address.

Also they would have to have been made by the same manufacturer. Different manufacturers get given their own range of mac addresses to program into their devices.

Dano · 27 Apr 2007 at 18:14

Nope, they were identical cards with identical MAC's, this was about 4 or 5 years ago.