[Confounded Also]

Is your MAC address ever transmitted via the web to sites you browse? Or anything else other than Cookies the sites use?

What ways do sites use to identify a specific machine, not just the IP address.

 

[LMiller7]

A MAC address is used only for communication in the local network. If you have a router that is as far as your computers MAC address will be known. Websites will never see or care about your AC address.

Your web browser will identify itself, the OS you are using, and some other information. The IP address is unique (usually) but your personal information is known only to your ISP and they will only reveal this to those with proper legal authorization.

Of course websites such as this forum and others where you must log in will have information you have provided.

 

[Confounded Also]

Your web browser will identify itself, the OS you are using, and some other information.

But nothing unique that could only be from one machine?

The IP address is unique (usually)

IP address here is Dynamic and is often changed.

 

[Daifne]

A MAC address is used only for communication in the local network. If you have a router that is as far as your computers MAC address will be known.

Some ISPs will also know the MAC addresses of devices attached to their modem. Time Warner does.

 

[sobeit]

Is your MAC address ever transmitted via the web to sites you browse? Or anything else other than Cookies the sites use?

What ways do sites use to identify a specific machine, not just the IP address.

my understanding is your devices mac address stops at the next device (usually router). the next device has its own mac address which shows up at the next device and so on.

https://askleo.com/can_a_mac_address_be_traced/

however, I know a mac address was used to traced to a local computer. (long story short) Basically what happened was child porn was traced to an ip address. The computer at the registered user home did not have the child porn but when they looked at logs in the router, they was able to use the mac address to prove a neighbour, who was sharing the network, was accessing the porn.

 

[Confounded Also]

my understanding is your devices mac address stops at the next device (usually router). the next device has its own mac address which shows up at the next device and so on.

So, a website such as this one couldn't even see the MAC address of the router/modem of the poster? They would only see one along the hops somewhere?

 

[koala]

There are ways for websites and forums to keep track of their visitors or members that don't involve using cookies or MAC addresses. You're never truly anonymous online.

From https://www.quora.com/How-do-I-prev...-address-without-using-a-random-MAC-generator

You can't be tracked by MAC address except by another computer connected to the same local area network as your computer. MAC addresses do not cross router boundaries, and nobody who basically isn't in the same building you are will ever see your MAC address.

 

[LMiller7]

my understanding is your devices mac address stops at the next device (usually router). the next device has its own mac address which shows up at the next device and so on.

https://askleo.com/can_a_mac_address_be_traced/

however, I know a mac address was used to traced to a local computer. (long story short) Basically what happened was child porn was traced to an ip address. The computer at the registered user home did not have the child porn but when they looked at logs in the router, they was able to use the mac address to prove a neighbour, who was sharing the network, was accessing the porn.

This has nothing to do with the original question.

By means of an IP address access to child porn was traced to a specific router and the local network it was a part of. The logs of that router contained the MAC address of a neighbors computer that made a connection to it. It was a part of the routers local network. There is no implication that this MAC address ever got any further than the router.

The packets of data leaving a computer contain the MAC address of it's network interface. But it doesn't get very far. When these packets reach the next network device the original MAC address is replaced by that of that device. There is no history of MAC address passed along, only that of the latest network device. When these data packets reach the Internet server they will contain the MAC address of closest network device it was connected to. There is no way such a server could ever see the MAC addresses of the client computers accessing it.

 

[Confounded Also]

I guess it probably doesn't really matter much since it appears the MAC address can be changed in many devices one way or another.

There are ways for websites and forums to keep track of their visitors or members that don't involve using cookies or MAC addresses. You're never truly anonymous online. https://www.quora.com/How-do-I-prev...-address-without-using-a-random-MAC-generator

And I'll guess y'all probably don't want to get into that here.

 

[koala]

And I'll guess y'all probably don't want to get into that here.

Correct, but the methods used are not secret, so get googling. :smile:

 

[pokeefe0001]

Is your MAC address ever transmitted via the web to sites you browse?

Technically, the answer could be "Yes".

If you use IPv6, your MAC address may be part of your IPv6 address. I don't know enough about IPv6 to make much sense of this, but if you see an IPv6 address that contains an FF at the end of one octet and FE at the beginning of the next octet, that IPv6 address contains an encoding of a MAC address. If on a Windows box issue the command ipconfig /all in a command window. Your IP addresses (both IPv4 and IPv6 will be displayed.

On my PCs, Windows does not provide any such addresses, but I see them generated by my routers. My Asus RT-N56U router has such an address for my IPv6 default gateway, but it is an IPv6 "link local" address; I think it is never seen outside of my LAN. I see another IPv6 address with this format - a global IPv6 address this time - as my DNS server. It looks like the MAC address of one of my router's ethernet ports might be visible to the outside world, but this address would not be visible to a internet web server ... I hope.