[gull] Probleme etrange DNS

[Marc SCHAEFER]

On Fri, Dec 05, 2003 at 09:17:52AM +0100, Daniel Cordey wrote:
> Qu'est-ce qui te gene dans le MX record (ou les) ? Je continue a penser qu'il 
> existe une forme d;ambiguite avec cette wildcard et la definition A de 
> 'lists'.

Il n'y a pas d'ambiguité, c'est dans le standard du système DNS.
Un wildcard ne prend jamais le pied sur une définition.

> remetrrait ce serveur sur le droit chemin.. Inutile de regarer le code de 
> bind9 s'il s'agit d'un serveur MS*...

Le RFC traitant du DNS dit: (STD-13, RFC-1035)
   
   In the previous algorithm, special treatment was given to RRs with owner
   names starting with the label "*".  Such RRs are called wildcards.
   Wildcard RRs can be thought of as instructions for synthesizing RRs.
   When the appropriate conditions are met, the name server creates RRs
   with an owner name equal to the query name and contents taken from the
   wildcard RRs.

   This facility is most often used to create a zone which will be used to
   forward mail from the Internet to some other mail system.  The general
   idea is that any name in that zone which is presented to server in a
   query will be assumed to exist, with certain properties, unless explicit
   evidence exists to the contrary.  Note that the use of the term zone
   here, instead of domain, is intentional; such defaults do not propagate
   across zone boundaries, although a subzone may choose to achieve that
   appearance by setting up similar defaults.

[ ... ]

   Wildcard RRs do not apply:

   - When the query is in another zone.  That is, delegation cancels
     the wildcard defaults.

   - When the query name or a name between the wildcard domain and
     the query name is know to exist.  For example, if a wildcard
     RR has an owner name of "*.X", and the zone also contains RRs
     attached to B.X, the wildcards would apply to queries for name
     Z.X (presuming there is no explicit information for Z.X), but
     not to B.X, A.B.X, or X.

On ne parle pas ici de code de référence, mais bien de standard.

PS: je n'installe plus de wildcard MX depuis longtemps, mais comme je
    l'ai déjà dit, c'était pour des raisons historiques.