How much can you find out with a mac adress

[Killerbenny04]

Hey, The Question is pretty Simple. If somebody else has my Phone MAC adress, what can they find out about me in the worst case?

[Jekub]

It's normally just manufacturer and maybe a modle number, you can always look up mac addresses using a variety of web tools such as this one
https://www.whatsmyip.org/mac-address-lookup/

[Killerbenny04]

3 minutes ago, Jekub said:

It's normally just manufacturer and maybe a modle number

So a Person that doesnt Know me, couldnt find out my name and stuff through that, right?

[Jekub]

Just now, Killerbenny04 said:

So a Person that doesnt Know me, couldnt find out my name and stuff through that, right?

Nope, MAC addresses are tied to the device not the user, your phone has had the same MAC address since it left the factory

[Killerbenny04]

Just now, Jekub said:

Nope, MAC addresses are tied to the device not the user, your phone has had the same MAC address since it left the factory

Ok thanks, just one last question, do you know if my internet provider like Telekom here in Germany can see my MAC adress?

[Sychic]

1 minute ago, Killerbenny04 said:

Ok thanks, just one last question, do you know if my internet provider like Telekom here in Germany can see my MAC adress?

Probably. 

[Killerbenny04]

Just now, Sychic said:

Probably. 

Ok, thanks.

[Meic]

20 minutes ago, Killerbenny04 said:

Ok thanks, just one last question, do you know if my internet provider like Telekom here in Germany can see my MAC adress?

MAC addresses are only transmitted within your local network so your ISP wont be able to see your Laptop/phone/PC MAC address.  They will however be able to see the MAC address of your modem/router.

[Killerbenny04]

Just now, Meic said:

MAC addresses are only transmitted within your local network so your ISP wont be able to see your Laptop/phone/PC MAC address.  They will however be able to see the MAC address of your modem/router.

Ok, and are Mac adresses also transmitted when youre in range of a wifi network, but not connected to it?

[Ravenbear]

20 minutes ago, Killerbenny04 said:

Ok, thanks.

There are ways to shall we say cloak one's mac address. But I will leave it at that, do not want to feel the ban hammer.

[Meic]

Just now, Killerbenny04 said:

Ok, and are Mac adresses also transmitted when youre in range of a wifi network, but not connected to it?

Yeah, that is correct.

[Killerbenny04]

1 minute ago, Meic said:

Yeah, that is correct.

Ok, thank you

[Meic]

3 minutes ago, Ravenbear said:

There are ways to shall we say cloak one's mac address. But I will leave it at that, do not want to feel the ban hammer. 

As it is a privacy concern, not a malicious process, I think we should be fine to discuss this. MAC address randomization is becoming quite common to stop WIFI providers from tracking individuals, it is a out of the box option in Android P: https://www.androidpolice.com/2018/03/08/android-p-feature-spotlight-per-network-mac-address-randomization-added-experimental-feature/

[Ravenbear]

1 minute ago, Meic said:

As it is a privacy concern, not a malicious process, I think we should be fine to discuss this. MAC address randomization is becoming quite common to stop WIFI providers from tracking individuals, it is a out of the box option in Android P: https://www.androidpolice.com/2018/03/08/android-p-feature-spotlight-per-network-mac-address-randomization-added-experimental-feature/

True, I see your point. Not enough coffee yet here. Thanks for bringing this up.

[Mira Yurizaki]

4 hours ago, Meic said:

As it is a privacy concern, not a malicious process, I think we should be fine to discuss this. MAC address randomization is becoming quite common to stop WIFI providers from tracking individuals, it is a out of the box option in Android P: https://www.androidpolice.com/2018/03/08/android-p-feature-spotlight-per-network-mac-address-randomization-added-experimental-feature/

Microsoft also added this recently to Windows: https://support.microsoft.com/en-us/help/4027925/windows-how-and-why-to-use-random-hardware-addresses

[Blade of Grass]

9 hours ago, Killerbenny04 said:

Ok thanks, just one last question, do you know if my internet provider like Telekom here in Germany can see my MAC adress?

A MAC address is the way that your device is identified on the network. Any sort of computer network that you connect to (wired, wifi, cellular, etc) will be able to see your MAC address because it is the only way for it to address your computer directly. But, MAC addresses do not leave the boundary of the network. Anytime you hit a router, the MAC address is no longer used and instead just an IP address is used. 

 

So if you connect to a wifi network, only the devices on the network can see your MAC address. If you connect to a LAN network, only the devices on the network can see your MAC address. If your cellphone connects to a cell tower, only the devices connected to the tower can you see your MAC address. 

 

Regarding if your MAC address can be seen if you’re not connect to the network—yes. Kinda of? Devices that connect to wifi networks are normally continually broadcasting little messages asking if networks they’ve previously connect to are available around them. As others have pointed out, a lot of operating systems now do they broadcasts with a random MAC address to alleviate the privacy concerns. 

[Guest]

I think you can change your MAC address if you really wanted. 

[Franck]

21 minutes ago, fpo said:

I think you can change your MAC address if you really wanted. 

Indeed you can and it's not super difficult (depending on the NIC and how the mac is stored)

[davehkiin]

As this is for Privacy, there are MAC Changers, in fact, most newer and modern devices randomly generate a new mac address everytime they connect to a network, even if it's a known network. This means for example, if you walk down a high street in a straight line, from shop 1 through to 20, and your phone says "Hello! I'm a phone, my WiFi is on! What's your name?" they will all respond with their SSID (Network Name) Like "Shop 1 Eatery" for you to connect

 

In theory you could get the times of all these handshakes, without ever connecting to any of them as retrieving the information was enough you could plot all the points of your device and say with some degree of confidence they walked this way at this time

 

But now with the randomization it just says well here there was a device that requested this, and for shop 2, 3, 4, n they all show differently, thus being unable to show any pattern.