Subject: Re: host not found?
To: Andreas Gustafsson <>
From: john heasley <>
List: current-users
Date: 04/15/2003 15:32:15
Tue, Apr 15, 2003 at 02:41:18PM -0700, Andreas Gustafsson:
> Chuck Yerkes writes:
> > Quoting Peter Seebach (
> > > So, Mozilla and a couple of other programs are consistently failing to look
> > > up any name with _'s in it.  The most obvious (and topical) example would
> > > be  "nslookup" finds it; "ping" doesn't.
> > 
> > You mean hosts that violate the DNS RFCS?
> They don't violate any DNS RFCs.  If they violate anything, it's
> RFC952, the "DOD Internet Host Table Specification", which predates
> the DNS.

952 appears to be "confirmed" by 1035 and both ammended by 1123 (which is
post dns), such that hostnames could begin with a digit.  1033 indicates
that any value (0-255) is possible, but should be limited to [a-z0-9_-]
and 1912 echos that but adds that 1033 is informational only ("voluntary").
but 1035 seems to limit it to [a-z0-9-] again.

follow the time-line of the rfc's?  the bog i have on hand (old as it is)

   RFC 1034 says only that domain names have characters in them, though it
   says so with enough fancy and indirection that it's hard to tell exactly.

   Generally, for second level domains (i.e., something you would get from
   InterNIC or from the US Domain Registrar and probably other ISO 3166
   country code TLDs), RFC 952 is thought to apply.  RFC 952 was about host
   names rather than domain names, but the rules seemed good enough.

        <domainname> ::= <hname>

        <hname> ::= <name>*["."<name>]
        <name>  ::= <let>[*[<let-or-digit-or-hyphen>]<let-or-digit>]

then see section 11 of 2181.