weird MX behavior

[Mark Andrews]

   RFC 1034, Section 3.6.2: "If a CNAME RR is present at a node,
   no other data should be present; this ensures that the data for
   a canonical name and its aliases cannot be different. This rule
   also insures that a cached CNAME can be used without checking
   with an authoritative server for other RR types."

> hi,
> 
> i'm running "bind-chroot-9.2.4-16.EL4" on "CentOS release 4.4 (Final)".
> 
> this config works fine ...
> ######################################################################
> $TTL 86400
> @               IN      SOA     ns1.mydomain.com.
> dns-admin.mydomain.com. (
>                                         2006100201      ; Serial
>                                         3600                 ; Refresh
>                                         600                   ; Retry
>                                         1209600            ; Expire
>                                         3600 )               ; Minimum
> 
>                 IN      NS      ns1.mydomain.com.
>                 IN      NS      ns2.mydomain.com.
> 
> funny            300     IN      A       10.10.10.10
> www.funny    300     IN      A       10.10.10.10
> @                300     IN      MX      10      mail.boss.com.
> @                300     IN      MX      20      mail1.boss.com.
> @                300     IN      MX      20      mail2.boss.com.
> funny            300     IN      MX      10      mail.boss.com.
> funny            300     IN      MX      20      mail1.boss.com.
> funny            300     IN      MX      20      mail2.boss.com.
> ######################################################################
>  i changed my config to
> ######################################################################
> $TTL 86400
> @               IN      SOA     ns1.mydomain.com.
> dns-admin.mydomain.com. (
>                                         2006100201      ; Serial
>                                         3600                 ; Refresh
>                                         600                   ; Retry
>                                         1209600            ; Expire
>                                         3600 )               ; Minimum
> 
>                 IN      NS      ns1.mydomain.com.
>                 IN      NS      ns2.mydomain.com.
> 
> funny            300     IN      CNAME   www.hugo.com.
> www.funny    300     IN      CNAME   www.hugo.com.
> @                300     IN      MX      10      mail.boss.com.
> @                300     IN      MX      20      mail1.boss.com.
> @                300     IN      MX      20      mail2.boss.com.
> funny            300     IN      MX      10      mail.boss.com.
> funny            300     IN      MX      20      mail1.boss.com.
> funny            300     IN      MX      20      mail2.boss.com.
> ######################################################################
> 
> mailing to funny.mydomain.com doesn't work anymore. i don't get any MX
> records for
> funny.mydomain.com !
> 
> so all i've been doing is that i changed the A record to a CNAME which
> i think hasn't got anything to do with mailing - or am i wrong ?
> 
> any help would be greatly appreciated
> 
> regards
> willi grundner
> 
> 
--
ISC Training!  October 16-20, 2006, in the San Francisco Bay Area,
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-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org