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Comment by gorgoiler | Hacker News Reader

Spoof the last three bytes all you like, but set the first three to 00:0E:AB. It’s unlikely, but it might give someone a chuckle.

”We’ve got a problem; someone’s misusing the crap out of the free wifi”

”Lets narrow it down by hardware: what kind of device are they using?”

”How should I know!?”

”Check the first three bytes of their MAC address; it’ll tell you the mfr”

”OK... checking now... yeah I see them... looking up their MAC... bingo... hey, what is ‘Cray Inc’?”

—

Better versions of this joke are available here:

http://standards-oui.ieee.org/oui/oui.txt

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or generate an address that is reserved for computers sold to the NSA (:

  #
  # 00-20-91 (hex)    J125, NATIONAL SECURITY AGENCY 
  # 002091 (base 16) J125, NATIONAL SECURITY AGENCY
  #
  $> NSA_MAC=$(echo "00:20:91:"`openssl rand -hex 3 \
    | sed 's/\(..\)/\1:/g; s/.$//'`)
  $> sudo ifconfig eth0 hw ether $NSA_MAC

But actually do people still bother with mac-spoofing in 2020? It's from a security/nw-admin pov next to useless (whitelist/filtering nor does it boost privacy of end-users). IMHO it gives people false sense of security and as a "practice" seems like a relic from the 90ies.

Plenty of captive portals use mac-addresses to identify if users have used the captive portal (or have paid the fee of entry if it’s a paid service).

Though I’m not sure I ever bothered to lookup someone’s MAC address.

Bluetooth and wifi mac spoofing is pretty common, both when scanning and connecting. Both iOS and android do it to certain degrees.

It does indeed boost privacy as wireless networks in public places have been trying to track phones this way for a while now.

I don't know how it is now, but I remember a lot of generic/no-name Androids using the Mediatek platform would have random MAC addresses (which change every time you re-enable WiFi) because the manufacturer didn't bother writing a fixed one, so the firmware automatically generates a random one to use.

My Pixel 4 uses a different mac every time it connects to a wifi network by default. You can disable it per-network.

This is not about privacy but access restriction (wifi in public hotspot limited to e.g. 30mins). And there it is still a very inexpensive solution i guess.

My university won't give me an IP, so I can't plug my laptop in. Solution was to fire up an old windows machine and grab the MAC off that.

I did politely ask for an IP before doing that, but they said it was a security risk.

Plenty useful back when Panera limited you to 30 minutes of wifi; no idea if they still do.

Their wifi solution tracked you by MAC -- I think it was Sonicwalls? -- so when you hit the 30-min limit you'd spoof the MAC, re-connect, then back to business as usual.

I'd usually comply when the place was bumping -- hard to work when it's loud and crazy -- but most of the time it was empty in the mornings and the 30-min-limit was pointless.

That's even _necessary_, as there are a few flag bits in the MAC address - broadcast, user-administrated-address, etc.

Just using a random value might give you "interesting" effects and lot of fun debugging those.

lots of fun ones. I'd do something like Boeing. There's an airplane on your wifi

I always use Sage (the accounting software folks) one of 00-80-2c as it's burned into my memory 30 years later after working on Sage Mainlan back in the days...

Looking at the list I'd go for SpaceX (00-26-12)

I chose Silicon Graphics (08:00:69) and it's fascinating to see that anyone else did, for any reason. For reference, my ISP hands out 2-8 IPv4 addresses, expiry indefinite (unless I power down), to clients connected to the cable modem. So my stack looks like

[Motorola Surfboard]->[4p 1GbE Switch]->[Linksys E3000 (08:00:69::)]

Depending on the mood of the ISP, I can have several other networks running from the 4-port switch. If I spoof those MACs repeatedly, I can get an arbitrary (within range) block of public IPs, and there's some seriously weird behavior in allocating those IPs (change my MAC 48 times in a row, end up on the same IP I had just lost from a power outage?)

[0]: https://en.wikipedia.org/wiki/Cray

I still don't get it. What makes this company particularly funny?

They make supercomputers, which are typically the size of a large room. It's quite unlikely you'll see one connecting to your free wifi.

Cray Inc? Pun of crying.

I'm pretty sure that's not the joke.

Cray computers were very famous in the 1970s and 1980s as highly specialist, highly parallel super computers with a fantastic marketing gimmick: not only were they the same size as 5 large refrigerators, they also came with their own built-in couch.

https://en.m.wikipedia.org/wiki/Cray-1

The idea of someone wheeling one of these into a cafe (because they are stealing the free wifi) causes me non zero amusement.

The NSA example from someone else is better.

Interestingly the only time I’ve ever had the pleasure of reclining on a Cray banquette was at the NSA’s cryptology museum at Ft Mead.

Shameless plug but I run a service that lets people look up the manufacturer by its MAC address: https://macvendors.com

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