Is MAC compulsary for a NIC?

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Is it possible for a NIC/ network adapter to communicate with internet if it is not assigned a MAC address ?

user2917687

Posted 2014-02-22T14:04:52.040

Reputation:

1It's a requirement for Ethernet, so pretty much yes. I doubt you will be able to get your NIC to function without one set. – deed02392 – 2014-02-22T14:20:22.947

please mention it as an answer and provide reference if any – None – 2014-02-22T14:46:49.797

1I think this question is a better fit on Superuser. Although a good question, it's not a question about information security. Your question may be migrated though (you can even flag it for migration), don't post a duplicate. – Luc – 2014-02-22T15:15:12.210

No your Network device cannot communicate without a mac address. Have a read on TCP/IP model work and – None – 2014-02-23T14:09:23.330

Answers

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I think the answer is no, it's not compulsory, but I'm not sure. It seems that when using a point-to-point protocol, you don't need a MAC address, but you can access the Internet (IP layer goes on top of PPP).

Storytime:

At school we had some lessons in network infrastructure. Everyone needed to use the school's virtual machine environment to do certain exercises, but of course since 60 people are using it at once, it's slow and annoying. A few of us ran it on their own laptops or had a VPS and used that instead.

One of the exercises was looking up the current ARP table with arp -a. This worked fine on all our laptops (Windows, Mac and Linux), but the VPS had issues. There did not seem to be any arp table at all!

We called the teacher and to our surprise, he had an answer: Because the VPS connected over a Point-to-Point Protocol (PPP), it didn't need an arp table because it didn't use ethernet at all. The IP protocol was used on top of PPP instead of on top of Ethernet.

This is all from memory and I hardly know anything about PPP (or any of its variants like PPPoE), but this is why I think the answer is no.

Luc

Posted 2014-02-22T14:04:52.040

Reputation: 2 013

Wow, I wish my school dared teach us anything so interesting in Computing. – deed02392 – 2014-02-22T15:55:54.580

@deed02392 I wish too ;). They didn't exactly tell us that on their own. We just happened to come across it and, by some miracle, the teacher (who is incredibly bad at explaining anything to anyone) happened to know this one fact. We have yet to figure out something else he knows besides what he attempts to teach. – Luc – 2014-02-22T21:38:33.373

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No, although your teacher worded the question in such a way that a pedant might find fringe outlier cases where the answer would be yes.

If we assume that you are on an Ethernet network which is connected to the Internet, then yes, @deed02392 is correct, a MAC address will be a requirement, as per the IEEE 802.3 standards - for example:

Ethernet is specified at selected speeds of operation; and uses a common media access control (MAC) specification and management information base (MIB).

While dominant, however, Ethernet is not the only network standard out there, and gateways permit diverse networks to talk. While I'm not familiar with one offhand, there's likely a network protocol out there that does not have a "media access control". Put a gateway in place that can talk to the Internet and boom, you have an adapter that can connect to the Internet without a MAC address.

If you can find an example of such a protocol I suspect that'll be worth extra credit. Look at full-duplex point-to-point protocols where the whole media access thing isn't an issue, for the obvious reason.

Good luck!

gowenfawr

Posted 2014-02-22T14:04:52.040

Reputation: 1 427

is ethernet standard used by wifi also ? apart from lan – None – 2014-03-01T13:26:36.603

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While 802.11 is often called "Wireless Ethernet", it's an equivalent of 802.3, not a child protocol. Nevertheless, it also uses MAC addresses - see IEEE 802.11

– gowenfawr – 2014-03-01T14:50:00.483

Re: 'While I'm not familiar with one offhand, there's likely a network protocol out there that does not have a "media access control"'. This is speculative and actually false. See Why do we still use Ethernet for more discussion

– Mike Pennington – 2014-03-01T18:54:08.377

1PPP doesn't have MAC addresses. ATM and Token Ring do. Fibre Channel does not, it has something called a World Wide Name (WWN) which is similar in nature but different in size. So, no, it's not false. – Alan Shutko – 2014-03-01T19:06:17.273