Super User
Super User

Questions tagged [mac-address]

A MAC address is a unique identifier for network adapters or network interface cards.

A MAC address is a level 2 unique identifier for network adapters or network interface cards.

A common practice in circumvention of network security is mac spoofing. Because of this, the use of MAC addresses to secure a network has been deprecated.

This is not to be confused with the tag , which refers to Apple Macintosh hardware.

493 questions
160
votes
2 answers

How to avoid exposing my MAC address when using IPv6?

On my Macs, each IPv6 address includes the MAC address of a specific computer (not of my router). Sites such as ipv6-test.com not only show it, but even tell me it belongs to an Apple computer. This feels like a super cookie, and might apply to…
Arjan
  • 31,511
134
votes
14 answers

What is the exact use of a MAC address?

I understand that IP addresses are hierarchical, so that routers throughout the internet know which direction to forward a packet. With MAC addresses, there is no hierarchy, and thus packet forwarding would not be possible. So, MAC addresses are not…
Vishnu Vivek
  • 761
89
votes
5 answers

How do I locate the MAC address of my computer?

I am unable to locate the MAC address in a new computer with Windows 7. I've tried ipconfig /all in the console to which I got no items match your search. I also tried getmac. A screen flashed very briefly with what appeared to be the…
Alibarsdad
58
votes
5 answers

Is looking for Wi-Fi access points purely passive?

Say I carry a Wi-Fi enabled phone or laptop through an area where there are WAPs. Assuming that I don't actively try to connect to them or otherwise interact with them, is it possible for the owner of that WAP to know that I was there? I'm asking…
Aric TenEyck
  • 1,007
53
votes
8 answers

How can I see my mac address on Ubuntu?

How can I see my mac address on Ubuntu?
Student
  • 837
40
votes
3 answers

Are MAC addresses unique when coming out of the factory?

According to Wikipedia: A Media Access Control address (MAC address) is a unique identifier assigned to network interfaces for communications on the physical network segment But how unique are MAC addresses on devices coming out of the factory? I…
Justin Ethier
  • 1,551
36
votes
3 answers

How is uniqueness of MAC addresses enforced?

Again and again I read that devices are uniquely identified by their MAC addresses. But how are MAC addresses determined? (And do they tell us anything about the device which they represent?)
Jellicle
  • 2,356
  • 4
  • 28
  • 32
30
votes
4 answers

What happens when two computers on the same network have the same MAC address?

I was reading an article on WEP cracking, which said that filtering MAC addresses was not enough, since there are tools to change what the computer reports as its MAC address. This made me wonder what would happen if someone uses the same MAC…
Manu
  • 3,050
28
votes
14 answers

IP Address vs MAC addresses

why do we need ip addresses if mac address is enough to identify the machine???
Jony
  • 385
  • 1
  • 3
  • 10
25
votes
3 answers

MAC addresses for virtual machines

As I understand it, MAC addresses are assigned to every physical device by the manufacturer. By extension, how are MAC addresses assigned to virtual machines - for example if I create a new virtual machine with an ISO of linux assigned? If it is…
Bendy
  • 413
24
votes
3 answers

Is your MAC address revealed when you hit up a website?

When you hit up a site, such as cnn.com, does the TCP/IP packet contain the MAC address of your network card? Could cnn.com theoretically record my MAC address?
AngryHacker
  • 19,327
21
votes
12 answers

I am confused about the way a common home router works: Shouldn’t the MAC addresses be enough to forward the information to the correct destination?

From what I've understood, the way it works is something like this: Why the necessity of associating private IP addresses to each one of the addresses connected? Shouldn’t the MAC addresses be enough to forward the information to the correct…
Ceccoclat
  • 329
20
votes
15 answers

How to generate a valid random MAC Address with bash shell

How can i generate a valid random mac adress with bash. The first half of the adress should always stay same like this 00-60-2F-xx-xx-xx just the x value should be generated random?
NES
  • 201
19
votes
1 answer

Why does Windows 11 display a different ethernet MAC (hardware) address than Linux?

I have a set of 1G Ethernet USB adapters. To keep them organized, I wanted to label them with MAC address so I could easily identify the correct interface when more than one was connected. I plugged three of them into a Linux machine, and got three…
tim11g
  • 2,058
19
votes
5 answers

Reasons not to assume device MAC address is unique

In a scenario where you control the provisioning of the hardware and can determine that all devices with the same hardware model do indeed have unique MAC addresses for their networking interfaces, are there any downsides to writing code that uses…
Matt Phillips
  • 313
1
2 3
…
32 33