[Samba] Problem with DNS configuration and "host" command . . .

[Steve Ankeny]

I'm following the instructions here --

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

I've successfully "tested" my domain controller --

adam at eagle:~$ smbclient -L localhost -U%
Domain=[SMBDOMAIN] OS=[Unix] Server=[Samba 4.1.18-Debian]

         Sharename       Type      Comment
         ---------       ----      -------
         netlogon        Disk
         sysvol          Disk
         IPC$            IPC       IPC Service (Samba 4.1.18-Debian)
Domain=[SMBDOMAIN] OS=[Unix] Server=[Samba 4.1.18-Debian]

         Server               Comment
         ---------            -------

         Workgroup            Master
         ---------            -------
         SMBDOMAIN.COM      HP-FRONTDESK
         WORKGROUP            EAGLE
adam at eagle:~$

adam at eagle:~$ smbclient //localhost/netlogon -UAdministrator -c 'ls'
Enter Administrator's password:
Domain=[SMBDOMAIN] OS=[Unix] Server=[Samba 4.1.18-Debian]
   .                                   D        0  Wed Nov  4 11:51:37 2015
   ..                                  D        0  Wed Nov  4 11:51:43 2015

                 49698 blocks of size 2097152. 46051 blocks available
adam at eagle:~$

*It's when I get to the "host" command that it fails* --

adam at eagle:~$ host -t SRV _ldap._tcp.eagle.smbdomain.com.
Host _ldap._tcp.eagle.smbdomain.com. not found: 3(NXDOMAIN)
adam at eagle:~$

Ubuntu "suggests" configuring a static ip in '/etc/network/interfaces' 
(instead of 'resolv.conf') --

adam at eagle:~$ cat /etc/network/interfaces

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
         address 192.168.121.149
         netmask 255.255.255.0
         gateway 192.168.121.1
         dns-search smbdomain.com
         dns-nameservers 192.168.121.149
adam at eagle:~$

Here's my 'smb.conf' (as provisioned, no edits) --

adam at eagle:~$ cat /etc/samba/smb.conf
# Global parameters
[global]
         workgroup = SMBDOMAIN
         realm = SMBDOMAIN.COM
         netbios name = EAGLE
         server role = active directory domain controller
         dns forwarder = 192.168.121.1
         idmap_ldb:use rfc2307 = yes

[netlogon]
         path = /var/lib/samba/sysvol/smbdomain.com/scripts
         read only = No

[sysvol]
         path = /var/lib/samba/sysvol
         read only = No
adam at eagle:~$

Any suggestions?  Thanks.