Re: network name 101100010100110.net

[Mark Andrews <marka () isc org>]

In message <20101018024021.GC8924 () vacation karoshi com.>, bmanning () vacation kar
oshi.com writes:
> On Sun, Oct 17, 2010 at 09:16:04PM -0500, James Hess wrote:
> > On Sat, Oct 16, 2010 at 11:46 PM, Day Domes <daydomes () gmail com> wrote:
> > > I have been tasked with coming up with a new name for are transit data
> > > network.  I am thinking of using 101100010100110.net does anyone see
> > > any issues with this?
> >
> > The domain-name starts with a digit, which is not really recommended,  RFC 
> 1034,
> > due to the fact a valid actual hostname  cannot start with a digit,
> > and, for example,
> > some MTAs/MUAs,  that comply with earlier versions of standards still in us
> e,
> > will possibly have a problem  sending e-mail to the flat domain, even
> > if the actual hostname is
> > something legal such as mail.101100010100110.net.
>
>       if there is code that old still out there, it desrves to die.
>       the leading character restriction was lifted when the company
>       3com was created.  its been nearly 18 years since that advice
>       held true.
>
> > Which goes back to one of the standard-provided definitions of domain
> > name syntax used by RFC 821 page 29:
> >
> > <domain> ::=  <element> | <element> "." <domain>
> > <element> ::= <name> | "#" <number> | "[" <dotnum> "]"
> > <mailbox> ::= <local-part> "@" <domain>
> > ...
> > <name> ::= <a> <ldh-str> <let-dig>
> > ...
> > <a> ::= any one of the 52 alphabetic characters A through Z
> >             in upper case and a through z in lower case
> > <d> ::= any one of the ten digits 0 through 9
>
>       at least three times in the past decade, the issues of RFC 821 
>       vs Domain lables has come up on the DNSEXT mailing list in the
>       IETF (or its predacessor).   RFC 821 hostnames are not the 
>       convention for Domain Labels, esp as we enter the age of 
>       Non-Ascii labels.

Correct but if you want to be able to send email to them then you
*also* need to follow RFC 821 as modified by RFC 1123 so effectively
you are limited to "<LD><LDH>*<LD>*{.<LD><LDH>*<LD>*}+".

If you want to buy "!#$%^&*.com" go ahead but please don't expect
anyone to change their mail software to support "bill@!#$%^&*.com"
as a email address.

The DNS has very liberal labels (any octet stream up to 63 octets
in length).  If you want to store information about a host, in the
DNS, using its name then you still need to abide by the rules for
naming hosts.  Yes this is spelt out in RFC 1035.

There are lots of RFCs which confuse "domain name" with "domain
style host name".  Or confuse "domain name" with "a host name stored
in the DNS".

Mark

>       That said, the world was much simpler last century.
>
> --bill
>
> > -- 
> > -Jh
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka () isc org