[Samba] Samba4 internal DNS not responding to DNS requests

[Lee Allen]

I am not able to get the Samba4 internal DNS server to respond to DNS
requests on the network.

I am running Samba4 4.1.0pre1-GIT-c1fb37d on my CentOS 6.3 system.  I
followed the instructions here:
https://wiki.samba.org/index.php/Samba_AD_DC_HOWTO

I configured Samba4 to use the internal DNS server.  My Samba4 server is
192.168.0.13. Its full hostname is ubuntu-ad.allenlan.net.  The realm is
ALLENLAN.NET.

The DNS testing section of the document passes:

$host -t SRV _ldap._tcp.allenlan.net.
    _ldap._tcp.allenlan.net has SRV record 0 100 389 ubuntu-ad.allenlan.net.
$host -t SRV _kerberos._udp.allenlan.net.
    _kerberos._udp.allenlan.net has SRV record 0 100 88
ubuntu-ad.allenlan.net.
$host -t A ubuntu-ad.allenlan.net.
    ubuntu-ad.allenlan.net has address 192.168.0.13

I configured my Windows XP system with a DNS of 192.168.0.13 (Samba4
server).
When I perform the Windows command "nslookup ubuntu-ad.allenlan.net" (or
any variation of that) it reports:
    DNS request timed out.
        timeout was 2 seconds.
    *** Can't find server name for address 192.168.0.13: Timed out
    (above 3 messages repeat again)
    Default servers are not available
    Server: UnKnown
    Address: 192.168.0.13

The Windows system can ping the Samba4 server by IP address.

Any help would be appreciated!  More configuration information below.

/etc/resolv.conf:
domain allenlan.net
nameserver 192.168.0.13

/usr/local/samba/etc/smb.conf:
[global]
        workgroup = ALLENLAN
        realm = ALLENLAN.NET
        netbios name = UBUNTU-AD
        server role = active directory domain controller
        dns forwarder = 192.168.0.1
        interfaces = 192.168.0.13 127.0.0.1
        bind interfaces only = yes
        log level = 3
        server services = smb, rpc, nbt, wrepl, ldap, cldap, kdc, drepl,
winbind, ntp_signd, kcc, dnsupdate, dns

/etc/hosts:
192.168.0.13    ubuntu-ad       ubuntu-ad.allenlan.net
127.0.0.1   localhost localhost.localdomain localhost4
localhost4.localdomain4
::1         localhost localhost.localdomain localhost6
localhost6.localdomain6

$hostname
ubuntu-ad.allenlan.net

Thank you.

Lee Allen