[Samba] Problems after DC upgrade

[Rowland Penny]

On Mon, 10 Feb 2025 02:24:31 +0000
Stephen Brandli via samba <samba at lists.samba.org> wrote:

> Well, it almost went okay.
> 
> Thumbnail: I had two DCs, running the latest in buster.  I created a
> new one running bookworm and 4.21.3.  I joined the new machine as a
> DC.  I then transferred the FSMO roles from one of the old ones and
> demoted that one.  My plan is to create a fourth new one and demote
> the other old one.  But, two problems:
> 
> 
>   1.  The dns on the new DC is not responding.  It did when I got it
> started, but in a reboot, it stopped responding.  Don't know why it's
> trying to bind to 0.0.0.0.  The hosts is set up correctly.  Log:

0.0.0.0 is another way of saying 'all IPv4 on this machine'

> 
> Feb 09 18:11:11 minister2 samba[88]:   dnsupdate_nameupdate_done:
> Failed DNS update with exit code 26 

That explains your missing dns records, samba_dnsupdate cannot add them.

> Feb 09 18:11:11 minister2
> samba[88]: [2025/02/09 18:11:11.816359,  0]
> source4/dsdb/dns/dns_update.c:85(dnsupdate_nameupdate_done) Feb 09
> 18:01:10 minister2 samba[88]:   dnsupdate_nameupdate_done: Failed DNS
> update with exit code 26 Feb 09 18:01:10 minister2 samba[88]:
> [2025/02/09 18:01:10.720661,  0]
> source4/dsdb/dns/dns_update.c:85(dnsupdate_nameupdate_done) Feb 09
> 18:01:07 minister2 winbindd[80]:   Copyright Andrew Tridgell and the
> Samba Team 1992-2024 Feb 09 18:01:07 minister2 winbindd[80]:
> winbindd version 4.21.3-Debian-4.21.3+dfsg-6~bpo12+1 started. Feb 09
> 18:01:07 minister2 winbindd[80]: [2025/02/09 18:01:07.051147,  0]
> source3/winbindd/winbindd.c:1447(main) Feb 09 18:01:07 minister2
> samba[90]:   Failed to bind to 0.0.0.0:53 TCP -
> NT_STATUS_ADDRESS_ALREADY_ASSOCIATED

Could it be that something like Bind9 is also running ?
If that is the case, when you joined the new DC, did you add
'--dns-backend=BIND9_DLZ' ?
If you didn't, you now have two choices, either turn off Bind9 or run
samba_upgradedns to change to Bind9 instead of the builtin dns server,
see here:

https://wiki.samba.org/index.php/Changing_the_DNS_Back_End_of_a_Samba_AD_DC

Rowland