Re: bind timeouts

On Tue, May 18, 2004 at 01:37:53AM -0500, Matthew D. Fuller wrote:
> On Tue, May 18, 2004 at 08:14:04AM +0200 I heard the voice of
> Christian Hiris, and lo! it spake thus:
> > 
> > As far as i know MX records _must_ have an A record.
> 
> RFC1035 states:
>     MX records cause type A additional section processing for the host
>     specified by EXCHANGE.  The use of MX RRs is explained in detail
>     in [RFC-974].
> 
> RFC974 says:
>     There is one other special case.  If the response contains an
>     answer which is a CNAME RR, it indicates that REMOTE is actually
>     an alias for some other domain name. The query should be repeated
>     with the canonical domain name.
> 
> RFC2821 obsoletes 974, but says substantially the same in regards to
> CNAME's.  So, by the RFC's it's allowed.
> 
> 
> For me, I think it's a bad practice.  But, hey...

You're not the only one. RFC 1912 ( Common DNS Operational and
Configuration Errors ) states :

Don't use CNAMEs in combination with RRs which point to other names
like MX, CNAME, PTR and NS.  (PTR is an exception if you want to
implement classless in-addr delegation.)  For example, this is
strongly discouraged:

    podunk.xx.      IN      MX      mailhost
    mailhost        IN      CNAME   mary
    mary            IN      A       1.2.3.4

-- 
Francois Tigeot