Underscores in host names

Wed May 18 22:29:39 UTC 2005

Paul Vixie wrote:

> putting these checks in for master zones, slave zones, and response
> data was a significant over-reach on my part.  THAT is what i'm
> apologizing for here. (and THAT is what CERT had asked me to do, since
> changing gethostbyaddr() would not, by itself, have protected Sendmail
> from newlines in its qf* files.)

Alright then. Personally I've found them useful at different times in
different places but that's some hair-splitting neither of us is
particularly interested in.

> just because you own an A RR doesn't make you a hostname.
> 
> just because you're pointed to by an MX RR doesn't make you a mailname.
> 
> (what a relief to finally be able to say that.)

At the risk of hair-splitting that I've already disclaimed, I'll halfway
agree (a host that doesn't accept connections arguably isn't a host) and
halfway disagree (the target of an MX must be a valid hostname). To ensure
that this thread dies now, I'll point out that I categorized some of this
as part of my second stab at the great white whale of i18n DNS [see
http://www.ehsco.com/misc/I-Ds/draft-hall-dns-datatypes-00.txt which
ensures nobody comes back]

-- 
Eric A. Hall                                        http://www.ehsco.com/
Internet Core Protocols          http://www.oreilly.com/catalog/coreprot/