[Samba] which DNS backend ?

mathias dufresne infractory at gmail.com
Tue Mar 1 10:23:27 UTC 2016


2016-02-29 0:05 GMT+01:00 Reindl Harald <h.reindl at thelounge.net>:

>
>
> Am 28.02.2016 um 23:54 schrieb Rowland penny:
>
>> On 28/02/16 22:42, Reindl Harald wrote:
>>
>>>
>>>
>>> Am 28.02.2016 um 23:10 schrieb Rowland penny:
>>>
>>>> On 28/02/16 21:56, Reindl Harald wrote:
>>>>
>>>>>
>>>>>
>>>>> Am 28.02.2016 um 22:22 schrieb John Gardeniers:
>>>>>
>>>>>> Thanks Rowland. Perhaps because I expected these basic issues to have
>>>>>> been resolved long ago I never thought to check the SOA records.
>>>>>> You are
>>>>>> perfectly correct - the second DC is not listed
>>>>>>
>>>>>
>>>>> since when is more than one NS listed in the SOA?
>>>>>
>>>>> http://rscott.org/dns/soa.html
>>>>>
>>>>> MNAME ("Primary NS") - This entry is the domain name of the name
>>>>> server that was the original source of the data (this entry MUST be
>>>>> your primary nameserver). This is your primary nameserver, and MUST be
>>>>> the one and only server that you ever update. You must not update the
>>>>> secondary server(s) -- they will update automatically, based on this
>>>>> the SOA record. Problem? This should be a fully qualified domain name .
>>>>>
>>>>> OK, I see where you are coming from, but, this is referring to a normal
>>>> dns server that replicates to other secondary dns servers. AD dns works
>>>> a little differently, all AD dns servers replicate dns records to each
>>>> other and each AD DC is supposed to be authoritative for the dns domain,
>>>> this does not happen if your first DC goes down when you are using the
>>>> internal dns server. As an aside, my first DC shutdown for some reason,
>>>> I didn't notice for a couple of hours, until I tried to 'ssh' into it, I
>>>> didn't notice because *everything* else just kept working on my
>>>> second DC
>>>>
>>>
>>> well, that's not the business of the SOA record
>>> it's a matter of NS-records
>>>
>>>
>> If you only have one Authoritative nameserver (which is what you have
>> with the internal dns) and it disappears, then you don't have *anything*
>> that will respond to a request for info about AD dns domain
>>
>
> sorry, but that's not a matter of SOA
>
> all your NS-records are authoritative, no matter if the yare master or
>
> slave, the format of the SOA record is pretty clear
>
> https://support.dnsimple.com/articles/soa-record/
> ns1.dnsimple.com admin.dnsimple.com 2013022001 86400 7200 604800 300
>
> nothing will change the SOA format because it's defined far away from
> samba and the implementation https://www.ietf.org/rfc/rfc1912.txt
>
> otherwise show me how you imageine a SOA record listing more than one
> nameserver would look like when the second filed is by defintion the admin
> contact
>
>
Several SOA is easy to design without breaking RFC: as every DNS server in
AD is able to modify the zone, every DNS server in AD is SOA. As any DNS
server is SOA and only one SOA can be returned, these DNS server must reply
"I am SOA".
10 DC running a DNS server.
One client asking to DC07 for SOA.
DC07 replies "SOA is DC07".
One client asking to DC02 for SOA.
DC02 replies "SOA is DC02".

This client ask for NS, all DNS server will reply 10 entries, one per DC
which is name server.

A DC don't need to be name server.


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