Friday, December 4, 2009

Wireless Hospitality and 00:18:f3:f7:6a:67

When something doesn't cost you much, it's easy to share. The marginal cost of Internet use is near zero, so why not keep your personal wireless network open, like McDonald's or Panera? Sure there are security risks from your neighbors and passers-by. But I don't think they are going to use my printer at will, and the security is not impossible to crack for people who really know how to do you harm.

In Europe this Summer, we were in places with a dozen wireless networks, all of which were locked down. We just wanted to check e-mail or post to a blog, actions which don't tax a network. But we had to literally hold our laptop out the window to pick up the stray free signal in Italy. Another time, I sat on a flower planter outside an apartment building with a free signal as an old lady stared at me. Not from her window; she was sitting a few feet away. I'm not good on picking up on nonverbal cues, and I used this to my advantage. Give a little wave, don't make eye contact, and keep reading e-mails.

So I don't want to be that person locking others out of vital communication. But this hospitality is not unlimited. I haven't seen a cheap wireless router that can partition a small portion of bandwidth for public use (I did see a DSL service in France that allocated some wireless for other DSL users which is a really worthwhile idea in dense areas).

Without limits, guest users can hog bandwidth. And that's what I noticed Thursday. Sites like Google that don't ever go down were timing out. Speeds were slower. I checked the router ( for the default D-Link configuration. See to look up the location of IP addresses). At the same time, one computer on my network was connecting to sites in
  • Augusta, Georgia
  • Hammond, Indiana
  • Salzburg, Austria
  • Philadelphia
  • Medina, NY
  • Ontario, CA
  • Bogota, Columbia
  • Saint Catharines
  • ON Canada
  • Swansea, Z1 Great Britain
  • Denton, TX
  • Olive Hill, KY
  • Paterson, NJ
  • Marysville, OH
  • Tokyo
  • Saint Clair Shores, MI
And the bandwidth use matched the number of sites. This probably represented P2P file sharing, where each computer downloads files from many other computers while serving up files for other computers. These downloads are often illegal rips of copyrighted material though some providers like NBC use them for legal downloads. It could also be a virus checking other computers for vulnerabilities. This is not a gracious use of someone else's network. So I locked that computer out. In our small neighborhood with a small wireless range, five users outside of our house, from other computers to iPhones, have connected to our network recently. I don't have a detailed analysis, so it's hard to know how much each of them has used the network.

So MAC address 00:18:f3:f7:6a:67 is blocked from our network. Sorry. (A MAC address is a unique identifier for a network card). I don't know which neighbor was using it or whether they were just accidentally connecting to the wrong network. Things cleared up after the problem computer was gone. I am still faced with how to be friendly yet not abusable.


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