A And Cname-record

[Mark Andrews]

> On 18 Jun 2020, at 08:31, Jukka Pakkanen <jukka.pakkanen at qnet.fi> wrote:
> 
> Yes but before going to RFC details one should check the basic spelling and syntax first…

I put the auotdiscover/autodiscover difference down to typo when entering the records by
hand into the email message.  Similarly absolute vs relative target name.

The fact that there was a error message that was cut-and-pasted indicates that the zone
actually does have CNAME and other data for name autodiscover.acig.com.sa and that Ejaz
said he was adding a A and CNAME at the same subdomain is enough by itself to discuss
that issue.

Mark
> -----Alkuperäinen viesti-----
> Lähettäjä: bind-users <bind-users-bounces at lists.isc.org> Puolesta Mark Andrews
> Lähetetty: 18. kesäkuuta 2020 0:27
> Vastaanottaja: Bogdan-Stefan Rotariu <bogdan at rotariu.ro>
> Kopio: bind-users at lists.isc.org
> Aihe: Re: A And Cname-record
> 
> 
> 
>> On 18 Jun 2020, at 07:56, Bogdan-Stefan Rotariu <bogdan at rotariu.ro> wrote:
>> 
>> Hi,
>> 
>>> On 18 Jun 2020, at 00:44, Ejaz Ahmed <mejaz at cyberia.net.sa> wrote:
>>> 
>>> when i am trying to add A and CNAME record together  for the same 
>>> subdomain, getting an error as below, you all kind  assistance would 
>>> be highly appreciated thanks in  advance
>>> 
>>> my records are as follows in zone
>>> 
>>> auotdiscover IN A 1.1.1.1
>>> autodiscover IN CNAME autodiscover.acig.com.sa
>>> 
>>> ======================================================
>>> dns_master_load: acig.com.sa.hosts:102: autodiscover.acig.com.sa: 
>>> CNAME and other data
>>> 
>>> zone acig.com.sa/IN: loading from master file acig.com.sa.hosts 
>>> failed: CNAME and other data
>>> 
>>> zone acig.com.sa/IN: not loaded due to errors
>> 
>> CNAME records cannot coexist with any other records last time I’ve 
>> checked. See section 2.4 from RFC1912[1]
>> 
>> [1] https://tools.ietf.org/html/rfc1912
> 
> Well it actually goes back to RFC 1034.  Unfortunately it wasn’t enforced in nameservers at the beginning and is still not enforced by some servers.
> 
> 3.6.2. Aliases and canonical names
> 
> ...
> 
> The domain system provides such a feature using the canonical name
> (CNAME) RR.  A CNAME RR identifies its owner name as an alias, and specifies the corresponding canonical name in the RDATA section of the RR.  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.
> 
> Mark
> 
>> —
>> Bogdan-Stefan Rotariu
>> 
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> 
> --
> Mark Andrews, ISC
> 1 Seymour St., Dundas Valley, NSW 2117, Australia
> PHONE: +61 2 9871 4742              INTERNET: marka at isc.org
> 
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-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742              INTERNET: marka at isc.org