Hacker News Reader

Comment by GHFigs | Hacker News Reader

I seem to recall there being some browser/OS combination that could not handle underscores at the beginning of addresses. What are you using, and can you access it with another browser?

View on HN

It's definitely the underscore: http://usesthis.com/ is accessible, as are all the other interviews, but http://_why.usesthis.com/ isn't.

And it doesn't seem to be the browser's fault:

  $ ping richard.stallman.usesthis.com
  PING richard.stallman.usesthis.com (74.207.245.100) 56(84) bytes of data.
  64 bytes from waferbaby.com (74.207.245.100): icmp_seq=1 ttl=51 time=63.6 ms

  $ ping _why.usesthis.com
  ping: unknown host _why.usesthis.com

So I can't resolve the domain name for some reason. This happens on both my home Gentoo box and my Slicehost Gentoo server.

It's a DNS resolution issue. Underscores in domain names are invalid, but some DNS host software still resolves them, while others stick to the spec.

I'd call this a fruit of this kind of DNS abuse. Yeah, OK, it looks nice, x.usesthis.com or whatever it is, but it forces you to make a new DNS lookup for each page, instead of using cached www.usesthis.com/something. And, as we can see, you can even make the address invalid. It's quite sad. :-/

Web content that is invalid according to one or more standards? Surely you must be joking.

Underscores have been allowed in domain names for quite some time. DNS based Service Discovery even requires their use.

EDIT: If I'm interpreting the specs correctly, underscores are fine in a domain name but not in a hostname.

On Linux, neither Chrome nor Firefox are working for me, yet:

    $ host _why.usesthis.com                                                       
    _why.usesthis.com has address 74.207.245.100

odd.

[Edit: Looking at darshan's post below, I understand why: host (part of the BIND distribution) uses its own resolver; everything else goes through the system facility (i.e. glibc). I still don't know how to fix it, though.]

I've got to it by visiting the main site and using Tamper Data to set the host in the HTTP headers to '_why.usesthis.com' - not idea but works!

Not the problem:

    $ curl http://_why.usesthis.com/
    curl: (6) Couldn't resolve host '_why.usesthis.com'

Reply on news.ycombinator.com