Re: Cell Phone Jammer For Sale MONIX MGB-1S

In article , TELECOM Digest Editor noted:

[TELECOM Digest Editor's Note: Other than the fact that she apparently > was not able to hook herself up to the network, I wonder how the > school would know what was or wasn't there. In other words, if she now > were to open the computer and install the original card in there > instead, how would the school ever find out, or do they search dorm > rooms looking for contraband hardware, etc? PAT]

Ignorance in action. Specific ranges of Ethernet addresses are assigned to given manufacturers. Which manufacturer "owns" which range is _public_data_.

Any device residing on the same LAN segment that can "see" Ethernet packets from a given machine can tell which brand of NIC is in that box.

All Ethernet cards on a LAN are required to have a _unique_ Ethernet address. So, manufacturers "build in" the uniqueness.

On some systems, with some cards, you can over-ride the built-in Ethernet address, and tell it to use an Ethernet address you specify. This is not an option under MS-Windows.

A _lot_ of schools require you to 'register' your computer (actually the NIC) with the institution before you can use it on the school network. And even then it will work *only* from your dorm room. The network infrastructure is built around 'secure' switches, and only accepts packets from a "known" Ethernet address on any given port.

This does wonders for being able to track down the perpetrator when, for example, one student tries hacking other student machines.