Comment by trotsky | Hacker News Reader

Comment by trotsky | Hacker News Reader

One bit in one gigabyte of RAM is 1 in 8,589,934,592. Wolfram Alpha estimates there are "over one billion computers" in the world.

Let's be charitable and say that every single one of those is connected to the internet 24x7 and they love microsoft so much that they visit the url every hour, so 24 times a day. To get even more accommodating, let's imagine every single computer in the world has a single bit error occur every hour as well, right before they head to microsoft.com.

In that case you'd expect about 3 hits a day.

I'm sure it can happen, but I'd be surprised if most of the traffic wasn't caused by other things. I can't be the only one who noticed in mic2osoft.com the number 2 is only two keys away from r. It may not be the most common typo in the world, but I bet the odds are a lot higher than 1 in 8.5 billion.

I almost think it's an inside joke, Kaminsky sounded just a wee bit too blown away while he was raving about the presentation last night. Or maybe that was just the booze tallking.

You assume error happens in RAM. Occurring on the wire seems far more likely. Don't forget that DNS is UDP and DNS servers cache their requests.

Wire transmissions are less likely to error because they have more checksums and other self-correcting mechanisms. A bad bit over the wire will get the entire data package dropped.

While I suspect you're right that the network path is more likely to error, udp does have a checksum that covers the entire payload so the DNS server would ignore the packet.

Also, the dns client is waiting for an address for the host that it requested. If it asks "where is alice?" and the dns server replies "bob is at x.x.x.x" it won't go there because the names don't match. So the error pretty much has to have happened on the client, but it could be a disk error, dma glitch, bug, malware or maybe a bad proxy/firewall.

The IP checksum is only 16 bits, so it will be fooled occassionally on a noisy line. Software that cares about correctness must use a proper error detection code of its own.

The UDP checksum is fairly weak, so a packet with two bit errors can pass the checksum.

Still, I would attribute hits on mic2soft.com to human error with higher likelihood than transmission errors. Human error is around 10^-2 [http://panko.shidler.hawaii.edu/HumanErr/Basic.htm] compared to transmission errors below 10^-9 for non-broken networks.

Thanks for doing the math. This is just ludicrous. I don't know much about domain registrations but is there no way to get a hold of a list of taken domains? (maybe there are lists just for some registrars where search/spam-bots can get a hold of it?)

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