[Samba] Cannot authenticate the administrator account

[Mike]

Louis and Rowland -- thank you, Gents!
Making progress.

Kerberos is operational and handing out tickets, but I was only able to
test using:

kinit administrator at EXAMPLE.COM

vs. the Samba AD DC HOWTO:  administrator at SAMDOM.EXAMPLE.COM

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Per Rowland's dns naming example - my hostname output:

~]# hostname -s
samba
~]# hostname -f
samba.internal.example.com
~]# hostname -d
internal.example.com

But, this appears incorrect:

~]# host -t SRV _ldap._tcp.example.com
_ldap._tcp.example.com has SRV record 0 100 389 samba.example.com.

~]# host -t SRV _ldap._tcp.internal.example.com
Host _ldap._tcp.internal.example.com not found: 3(NXDOMAIN)

~]# host -t SRV _ldap._tcp.samba.internal.example.com
Host _ldap._tcp.samba.internal.example.com not found: 3(NXDOMAIN)

~]# host -t SRV _ldap._tcp.samba.example.com
Host _ldap._tcp.samba.example.com not found: 3(NXDOMAIN)

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The same results as above when tesing:

~]# host -t SRV _kerberos._udp.example.com
_kerberos._udp.mwllc.info has SRV record 0 100 88 samba.example.com.

and the other combinations report "not found: 3 (NXDOMAIN)


Did I simply provision the REALM or domain incorrectly from the start?
testparm -v output shows I provided the following:

workgroup = INTERNAL
realm = EXAMPLE.COM
netbios name = SAMBA