In article <glnemv$10n...@sf1.isc.org>, Matus UHLAR - fantomas <uh...@fantomas.sk> wrote:
> On 27.01.09 08:46, Al Stu wrote: > > So then you disagree that the following example returns a valid address > > record for srv1? > > > > srv1 300 IN A 1.2.3.4 > > mx1 300 IN CNAME srv1.xyz.com. > > @ 300 IN MX 1 mx1.xyz.com. > > > > 1) Select Target Host: > > The MX query for xyz.com delivers mx1.xyz.com which is a CNAME. > > > > 2) Get Target Host Address: > > The A query for mx1.xyz.com delivers the address (A) record of > > srv1.xyz.com, 1.2.3.4, and also delivers the alias (CNAME) record of > > "mx1.xyz.com". > > They are two queries. If mx1 would be an A, it would be returned in the > first query. Since it's a CNAME, the IP is not returned in the MX query. So what? If the IP isn't in the additional section, the client will do its own A query. There's no requirement that the response to the MX record include the A record. It's nice if it does, since it saves a query, but this is just an optimization. -- Barry Margolin, bar...@alum.mit.edu Arlington, MA *** PLEASE don't copy me on replies, I'll read them in the group *** _______________________________________________ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
