[Samba] Joining a Linux domain member to an actual Windows AD Domain

[Mark Foley]

I am attempting to join a Linux host as a domain member to a Windows AD domain.
I am following the instructions in https://wiki.samba.org/index.php/Setting_up_Samba_as_a_Domain_Member

I am at the section in that doc, "Resolving SRV Records" which says, "Active
Directory (AD) uses SRV records to locate services, such as Kerberos and LDAP. 
To verify that SRV records are resolved correctly, use the nslookup interactive
shell:", and I go ahead and do the suggested commands:

# nslookup
> set type=SRV
> _ldap._tcp.cwaserver1.cwa4502.local
Server:         192.168.1.5
Address:        192.168.1.5#53

** server can't find _ldap._tcp.cwaserver1.cwa4502.local: NXDOMAIN

# host -t SRV _ldap._tcp.cwaserver1.cwa4502.local
Host _ldap._tcp.cwaserver1.cwa4502.local not found: 3(NXDOMAIN)

As you can see, this test appears to be failing. 

Other Windows workstations are connected to this Domain w/o problem.  Is it
critical for this SRV record thing to work? If so, what suggestions are there on
what needs to be done in the domain controller to fix this?

Thanks --Mark