5 ms·

Ordinarily I'd agree, but a starting hyphen isn't valid in a domain name anyway, so it's harmless. RFC 1035: "The labels [a grammar production rule for domain n

Ordinarily I'd agree, but a starting hyphen isn't valid in a domain name anyway, so it's harmless. RFC 1035: "The labels [a grammar production rule for domain names] must follow the rules for ARPANET host names. They must start with a letter, end with a letter or digit, and have as interior characters only letters, digits, and hyphen. There are also some restrictions on the length. Labels must be 63 characters or less." (And by the way, neither is a leading dot, which I use to my advantage to define hostname aliases in ~/.ssh/config which I can be sure will never clash with anything.)

LukeShu 9y ago
> They must start with a letter By the RFCs, that's true; but if you think it's true in practice, then 4chan.org would like a word with you.
- pwdisswordfish 9y ago
  Right... but the no-starting-hyphen rule seems to be more universally accepted. ... ...Oh, fuck me. I just found https://archive.fo/T0WcV https://archive.fo/T0WcV ... (archive.is link because Firefox won't open it directly)
  - geofft 9y ago
    I think it's not so much Firefox as your OS - if you're on a GNU platform, glibc will refuse to resolve a hostname that starts with a hyphen (it won't even attempt the resolution), but macOS's libc resolver is totally fine with it. I forget what Windows does.
    - danarmak 9y ago
      Chrome and Firefox on Windows 10 both open http://-emmawatson.tumblr.com/ http://-emmawatson.tumblr.com/ without trouble.
      - Godel_unicode 9y ago
        Doesn't work on chrome for Android, DNS error.
      - Klathmon 9y ago
        My chrome will not open that website (gives a DNS resolution error). Chrome: 61.0.3163.31 (Official Build) beta (64-bit) Windows: Microsoft Windows 10 Pro 10.0.15063 Build 15063 My DNS is pointed at my router which is forwarding requests to Google's 8.8.8.8 DNS servers.
  - frandroid 9y ago
    Huh? I just opened it in Firefox Nightly...
  - js2 9y ago
    Decade old glibc issue: gethostbyname() cant resolve names starting/ending with "-" https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/144431 https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/144431
    - gazarsgo 9y ago
      I ran across this a couple years ago because Tumblr let you use a leading - for your subdomain... I remember being so shocked reading this thread, but clearly nobody on that discussion had heard of Tumblr at the time. Very surreal.
- geofft 9y ago
  https://tools.ietf.org/html/rfc1123#page-13 https://tools.ietf.org/html/rfc1123#page-13 The syntax of a legal Internet host name was specified in RFC-952 [DNS:4]. One aspect of host name syntax is hereby changed: the restriction on the first character is relaxed to allow either a letter or a digit. Host software MUST support this more liberal syntax.
  - MikeTLive 9y ago
    doesn't say it must not accept anything other than a letter or a digit and so, to cover future leniency changes, i would not be surprised to see poetic-license taken such that they allow damn near anything in an unreliable way.
  - bostik 9y ago
    Hmm.. that's from 1989. 3Com would have still been a fairly respected network hardware vendor. I have a strange feeling '3com.com' would have been a consideration when this change was proposed.

LukeShu 9y ago

> They must start with a letter By the RFCs, that's true; but if you think it's true in practice, then 4chan.org would like a word with you.

pwdisswordfish 9y ago
Right... but the no-starting-hyphen rule seems to be more universally accepted. ... ...Oh, fuck me. I just found https://archive.fo/T0WcV https://archive.fo/T0WcV ... (archive.is link because Firefox won't open it directly)
- geofft 9y ago
  I think it's not so much Firefox as your OS - if you're on a GNU platform, glibc will refuse to resolve a hostname that starts with a hyphen (it won't even attempt the resolution), but macOS's libc resolver is totally fine with it. I forget what Windows does.
  - danarmak 9y ago
    Chrome and Firefox on Windows 10 both open http://-emmawatson.tumblr.com/ http://-emmawatson.tumblr.com/ without trouble.
    - Godel_unicode 9y ago
      Doesn't work on chrome for Android, DNS error.
    - Klathmon 9y ago
      My chrome will not open that website (gives a DNS resolution error). Chrome: 61.0.3163.31 (Official Build) beta (64-bit) Windows: Microsoft Windows 10 Pro 10.0.15063 Build 15063 My DNS is pointed at my router which is forwarding requests to Google's 8.8.8.8 DNS servers.
- frandroid 9y ago
  Huh? I just opened it in Firefox Nightly...
- js2 9y ago
  Decade old glibc issue: gethostbyname() cant resolve names starting/ending with "-" https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/144431 https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/144431
  - gazarsgo 9y ago
    I ran across this a couple years ago because Tumblr let you use a leading - for your subdomain... I remember being so shocked reading this thread, but clearly nobody on that discussion had heard of Tumblr at the time. Very surreal.
geofft 9y ago
https://tools.ietf.org/html/rfc1123#page-13 https://tools.ietf.org/html/rfc1123#page-13 The syntax of a legal Internet host name was specified in RFC-952 [DNS:4]. One aspect of host name syntax is hereby changed: the restriction on the first character is relaxed to allow either a letter or a digit. Host software MUST support this more liberal syntax.
- MikeTLive 9y ago
  doesn't say it must not accept anything other than a letter or a digit and so, to cover future leniency changes, i would not be surprised to see poetic-license taken such that they allow damn near anything in an unreliable way.
- bostik 9y ago
  Hmm.. that's from 1989. 3Com would have still been a fairly respected network hardware vendor. I have a strange feeling '3com.com' would have been a consideration when this change was proposed.