[Samba] Failed to find a writeable DC

[Rowland Penny]

On Wed, 15 Oct 2025 16:06:19 +0200 (CEST)
Fabrizio Rompani <fabrizio.rompani at yetopen.com> wrote:

> 
> Finally, is everything in the same subnet e.g. 192.168.1.2/24
> 
> NO , the 2 hosts have public ips , exposed on internet . 
> is just  a momentary configuration to "transfer " the domain from one
> host to another. 
> 
> 
> the other questions are all yes. 
> 
> thank's 
> rf
> 

Excuse me will I scream:

NOOOOOOO ;-)

It isn't a good idea to expose any AD DC to the internet,
apart from that, it is likely your problem, your 'new' DC probably
cannot find your old DC because they are in separate unrouted subnets.

I would try joining your 'new' DC in the same subnet, then move it to
it new subnet, ensuring all the IPs in AD etc are changed. If you are
removing the old DC, I would backup the domain using samba-tool before
doing anything further, then join the new DC and demote the old, them
change the IPs.
If you are retaining the old DC, then read up on sites and services,
create a new site and subnet and join your new DC to the new site.

Rowland