[Samba] Unable to join domain

[Rowland Penny]

On Mon, 2021-10-11 at 15:01 -0400, Rob Campbell wrote:
> The Debian DC DC01 seems to be just fine.  I have no issues with
> that.
> 
> FSDC02 is Fedora Server which I was told could be a member or a
> standalone server.  I want to use it as a member.  It seems that I am
> able to join it as a member but the DNS is not registering.  FSDC02
> was test-server.lan before I was told that I needed to use Debian as
> the first DC.  So I changed test-server.lan to FSDC02 and removed the
> samba configuration I had successfully running on it as a standalone
> file server, created a Debian vm, changed test-server.lan to fsdc02
> and set Debian to DC01.test-server.lan.  I then went through the wiki
> for Samba as an AD DC.  Once that was working as expected I started
> working on setting fsdc02 up as a member.  I can rename it to FS01
> for clarity but last time I had a problem removing but I can try it
> again.

A standalone server is not and never can be a member of a domain.

When you set up a domain, you need to choose a dns domain and then any
domain members (DC's, RODC's, Unix domain members and Windows PC's)
need to use this dns domain. You then use different hostnames to
identify each computer. Lets say your dns domain is
'samdom.example.com', you would then have FQDN's in the following
format:
dc1.samdom.example.com
rodc1.samdom.example.com
unix.samdom.example.com
windows.samdom.example.com

They all use 'samdom.example.com' for the dns domain and
'SAMDOM.EXAMPLE.COM' for the realm. 
This dns information is all stored in the AD database and can be
read/written by each DC, this is why AD dns is known as multi-master.

As I said previously, using the fedora packages for a DC is still
considered experimental, but they can be used for a Unix domain member
because the KDC on a Debian DC will be using Heimdal.

>From what I seen in the OP's posts, I think he needs to check dns, do
all his machines use the same dns domain name ? can each machine ping
any other machine by short hostname and fqdn ?

Rowland