[Samba] Samba DNS fails when queried with nslookup commands

[L.P.H. van Belle]

> -----Oorspronkelijk bericht-----
> Van: James Atwell [mailto:james.atwell365 at gmail.com] 
> Verzonden: donderdag 13 augustus 2020 16:48
> Aan: samba at lists.samba.org
> CC: L.P.H. van Belle
> Onderwerp: Re: [Samba] Samba DNS fails when queried with 
> nslookup commands
> 
> 
> On 8/13/2020 9:57 AM, L.P.H. van Belle via samba wrote:
> > Hai James,
> >
> > Thanks, thats exactly what we needed.
> > I'll comment below.
> >
> >
> > ** SNIP **
> 
> 
> Louis,
> 
>        Couldn't figure out how to remove 127.0.0.53 from 
> resolv.conf so 
> I removed systemd-resolve per Rowlands post.  I then removed the 
> forwarders from my smb.conf and rebooted. Nslookup partially 
> worked as 
> it used the other DC in the network to resolve and complained soldc4 
> couldn't do recursive queries.  I added back in the 
> forwarders and dns 
> resolution appeared to work correctly except on soldc4. 

> Except for one minor issue still remains. See output below.

This is sufficient. 

systemctl disable systemd-resolved 
systemctl mask systemd-resolved 

And it wont start again.


> 
> @soldc4:~# nslookup soldc4
> Server:         172.16.23.30
> Address:        172.16.23.30#53

nslookup $(hostname -f) 
Should work. 


> 
> Non-authoritative answer:
> *** Can't find soldc4: No answer
This is a correct reply. 

> 
> root at soldc4:~# nslookup soldc4.domain.local
> Server:         172.16.23.30
> Address:        172.16.23.30#53
> 
> Name:   soldc4.domain.local
> Address: 172.16.23.30

So its in fqdn correct. 

If you want nslookup soldc4 to work, then you need the search line in resolv.conf


> 
> 
> The issue now is since I disabled systemd-resolve it also removed my 
> search domain from resolv.conf.
> 
> @soldc4:~$ cat /etc/resolv.conf
> # Dynamic resolv.conf(5) file for glibc resolver(3) generated by 
> resolvconf(8)
> #     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE 
> OVERWRITTEN
> # 127.0.0.53 is the systemd-resolved stub resolver.
> # run "systemd-resolve --status" to see details about the actual 
> nameservers.
> nameserver 172.16.23.30
> nameserver 172.16.23.28

rm /etc/resolv.conf 
editor /etc/resolv.conf 
search domain.local
nameserver 172.16.23.30
nameserver 172.16.23.28

Also one tip here, if you setup resolv.conf manualy 
Add : 
search domain.local
nameserver 172.16.23.28
nameserver 172.16.23.30

Reboot
Check the dns. 
If ok, then change : 
search domain.local
nameserver 172.16.23.30
nameserver 172.16.23.28
# Note, ad join DC1 is first, after join, you can switch the nameserver lines. 


> 
> 
> Where do I need to add my search domain as I already added to 
> my netplan 
> config and 50-cloud.init.yaml is the only file to config.
> 
>   ls -la /etc/netplan/
> total 12
> drwxr-xr-x   2 root root 4096 Aug 13 10:03 .
> drwxr-xr-x 113 root root 4096 Aug 13 10:04 ..
> -rw-r--r--   1 root root  584 May 28 19:36 50-cloud-init.yaml
> 
> Thanks.

If you config through netplan is/was correct, then and you use systemd-resolved 
It should always be correct. 

But thats a choice, set resolv.conf manualy or set it in you network config. 

Currently, i preffer through systemd-networked its config.  ( on debian ) 
Ubuntu its default is netplan.


So far, 

Greetz, 

Louis