Re: A Comment on 9. [1] of the requirements document.

[George Belotsky <george@register.com>]

Scott:

Section 2.3.1 is the **preferred name syntax**, as clearly indicated.

It says explicitly in 2.3.3 that "... future additions beyond current
usage may need to use the full binary octet capabilities in names, so
attempts to store domain names in 7-bit ASCII or use of special bytes
to terminate labels, etc., should be avoided".

Hence, it would appear that an RFC 1035-compliant implementation must
preserve all 8 bits of each octet whenever possible.

In sum, RFC 1035 says 2 things:

         (i) store names into DNS as per the ABNF in 2.3.1.
        (ii) when implementing DNS software, ensure that it
             will be able to support all 8 bits per character
             (except the null) as per 2.3.3.

Thus, RFC 1035 does not restrict the encoding in the DNS to the
7-bit subset -- in fact, it strongly discourages such a 
restriction.

What RFC 1035 does restrict is what a user, system administrator,
etc. is allowed to put in the DNS.

While the above distinctions are subtle, they are sometimes very
relevant.  For example, getting it wrong can result in non-compliant 
implementations, which may be significant.

George.

On Fri, Apr 13, 2001 at 06:05:48PM -0400, Hollenbeck, Scott wrote:
> > -----Original Message-----
> > From: George Belotsky [mailto:george@register.com]
> > Sent: Friday, April 13, 2001 3:01 PM
> > To: Hollenbeck, Scott
> > Cc: ietf-provreg@cafax.se
> > Subject: Re: A Comment on 9. [1] of the requirements document.
> > 
> > 
> > Please note 2.3.3.  You are specifically told to avoid storing
> > labels as 7-bit ASCII.
> 
> The ABNF specification provided in RFC1035 section 2.3.1 is unambiguous WRT
> labels used to represent domain and host names.
> 
> <Scott/>

-- 
-----------------------------
George Belotsky
Senior Software Architect
Register.com, inc.
george@register.com
212-798-9127 (phone)
212-798-9876 (fax)