Question about authoritative server and AA Authoritative Answer

Wed Jan 17 12:59:03 UTC 2024

‌

‌
Dear Greg,
Dear Mark,

Once more thank you for your replies. Please see highlighted words below.

I confirm that 172.16.0.254 is the dns authoritative server.

 'pc1' means 'a generic computer on a local area network'. It could be a web server, a file server, a mail server. For a small structure with fixed ip addresses only, it could be a user's pc. On pc1 there is a fresh install of ubuntu 22.04 with only a few network settings (dhcp, dns, gateway). I created it only to test various network settings (dynamic dns, fixed ip address, dhcp provided ip address, ...). 

For this specific question about authoritative server, pc1 has a fixed ip address. Ubuntu's networkd-resolved local dns caching and stub is disabled, (Cache=no, DNSStubListener=no). For this specific question, I have only two computers, one authoritative non-recursive dns server and a generic computer named pc1. 

Please have a look at the highlighted text below to understand my question :

Command dig pc1.reseau1.lan ns

;; Got answer:

;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 56002

;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

AUTHORITY: 1 : this is ok.

Command dig pc1.reseau1.lan 

;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 57670

;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

Why AUTHORITY: 0 and not AUTHORITY: 1 ???

De : "Greg Choules" <gregchoules+bindusers at googlemail.com>
A : pub.diemer29 at laposte.net,bind-users at lists.isc.org
Envoyé: lundi 15 Janvier 2024 18:27
Objet : Re: Question about authoritative server and AA Authoritative Answer

Hi again and thanks for that.
I'm still not exactly clear on the setup. I think the auth server is 172.16.0.254 (I don't know what pc1 is).

But anyway, looking at your results I see the AA bit for everything. It appears that these queries both went directly to the auth server because recursion is disabled and it told you so.

======

# pc1 at pc1:~
dig pc1.reseau1.lan
```

```txt
; <<>> DiG 9.18.18-0ubuntu0.22.04.1-Ubuntu <<>> pc1.reseau1.lan
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 57670
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

# ns1 at ns1:~
dig pc1.reseau1.lan
```

```txt
; <<>> DiG 9.18.18-0ubuntu0.22.04.1-Ubuntu <<>> pc1.reseau1.lan
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 2379
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

======

So unless I'm missing something I don't see your problem.

Cheers, Greg

On Mon, 15 Jan 2024 at 15:24, <pub.diemer29 at laposte.net> wrote:

D‌ear Greg, 

Thank you for your reply.

Please find attached the markdown file  with all the commands and text from the terminal.

In /etc/resolv.conf I had "127.0.0.53" so I disabled the DNSStubListener from systemd-resolved. I have netplan and networkd.

Kind Regards,

Michel Diemer.

De : "Greg Choules"
A : pub.diemer29 at laposte.net,bind-users at lists.isc.org
Envoyé: dimanche 14 Janvier 2024 23:28
Objet : Re: Question about authoritative server and AA Authoritative Answer

Hi Michel.
Please can you send the following information:

- name and IP address of the authoritative server

- the full contents of the zone file for "reseau1.lan"

- name and IP address of the other server - what does this server do?

- What is the machine "pc1", on which you are running the digs?

- the file "/etc/resolv.conf" on "pc1"

Please also re-send the digs with full output.

When you send information, please send it as text, not screenshots.

Thanks, Greg

On Sun, 14 Jan 2024 at 22:04, Michel Diemer via bind-users <bind-users at lists.isc.org> wrote:

‌Ders bind users,

I have already asked a similar question which was more about DNS in general , this one is very specific about the AA bit.

Today's question is : « "dig pc1.reseau1.lan ns" show AUTHORITY: 1 and "dig pc1.reseau1.lan" shows AUTHORITY: 0. Which setting or knowledge am I missing ? If possible, how to get AA answers for QNAME queries ? »

I have set up two virtual machines on a virtual local network using Oracle VirtualBox. One machine is a DNS authoritative-only server. The zone is named "reseau1.lan" and defined only in bind9 zone files. If I really have to, I will name it "reseau1.home.arpa" according to RFC 8375. (I chose .lan inspired by RFC 6762 appendix G). The IP address of the DNS server is 172.16.0.254 and the IP address of pc1 is 172.16.0.21.

dig soa reseau1.lan : the AA bit is set, which is what I am looking for

͏‌ ͏‌ ͏‌ 

 dig pc1.reseau1.lan ns :  the AA bit is set

͏‌ ͏‌ ͏‌ ͏‌ 

dig pc1.reseau1.lan : the AA bit is not set. Why ? Which setting or knowledge am I missing ?

Below my "named.conf.options" file

͏‌ 

͏‌ ͏‌ ͏‌ ͏‌ 
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