Damm,
Just chopped my finger with a hatchet.
No blood, just a lot of swelling, and a weird purple colour.
Will holding cold beer against it improve the prognosis?
Wife seems to think I may have done it "deliberately", just for the medication, but I was gonna drink it anyway.
Yeah,
So every layer 2 datagram has your MAC / UID address encoded into an 11 byte field they called "padding".
There is also a 2 bit NSA GCHQ check field, so every datagram you send has gone to the NSA , with a sequence number, and a checksum, so even if they drop a few packets, they can still build the message.
Also, whenever you make a connection to any website, your ISP reserves a path for all your data to travel through, this happens on all the routers to your destination, and whether you use vpn, encryption, spoofing, whatever, that reserved tunnel is easily available to those who would try to trace it.
It's a lot harder to hide, than you might think.
When I was doing my Cisco quals, years ago, we used Nmap to packet sniff, and we noticed, that every packet we sent, without exception, had our MAC address in it.
We thought this was strange, because there are other address fields, for routing, and this was not one of them.
So we used Nmap to spoof our MAC address, and everything worked fine, but then FCC said you must have a UID burned into a chip, that cannot be spoofed, or we will kill your license to trade in the USA.
So from 2002 onwards, every NIC ever made, has burned an encrypted version of this into the padding field.