Information Security Stack Exchange is a question and answer site for information security professionals. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Will a USB modem send my computer's MAC address to the Internet service provider when I am using it?

I mean, if two computers use the same USB modem will the Internet service provider know that two computers are sharing that modem?

share|improve this question
Define USB modem. – Lucas Kauffman Mar 9 '13 at 19:23

Your computer doesn't have a MAC address on its own, a MAC address is something related to the network adapter. So your USB Modem (I'm assuming you're talking about those 3G/4G USB Modems) has its own IMEI (or MAC address in some cases), and when you use it to connect to the Internet your ISP will see it.

If your ISP doesn't require you to install an application† to use for the connection, then I don't see how they can find out that you're using the same USB Modem on two different computers.

† Such application might gather some data about your computer and come up with a sort-of identifying signature comprised of information about OS installation and/or hardware.

share|improve this answer
Since MAC addresses are specific to Ethernet devices, I don't see why a 3G/4G USB modem would have one at all. – Xander Mar 9 '13 at 20:50
What do you know, it looks like they might after all. Will wonders never cease? – Xander Mar 9 '13 at 20:53
Ok, now I'm having a converstation with myself in the comments, but whatever. Looks like 4G WiMax may have a MAC address for the device (which superficially makes sense, don't know about technically) but 3G/4G LTE doesn't appear to, which really does make sense. – Xander Mar 9 '13 at 21:00
@Xander, 1- Thank you for brining this to my attention, I mistakenly said MAC instead of IMEI (I have corrected the answer), but I didn't know about 4G WiMAX. 2- MAC isn't exclusive to Ethernet devices, it's used in many other IEEE 802 standards for example, IEEE 802.15.1 (Bluetooth). – Adi Mar 9 '13 at 21:40
Ah, true, they are indeed going exist for any 802.x protocol. Modem communications typically are not, however, 802.x based. Cheers for differentiating. – Xander Mar 9 '13 at 22:53

protected by Community Aug 22 '14 at 13:52

Thank you for your interest in this question. Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site (the association bonus does not count).

Would you like to answer one of these unanswered questions instead?

Not the answer you're looking for? Browse other questions tagged or ask your own question.