Backup Domain Controller - DNS doesn't work

[Jan B Kinander]

Hi,
I run debian wheezy and have installed a second domain controller from
current git and I was able to successfully follow the howto:
http://wiki.samba.org/index.php/Samba4_joining_a_domain
All the replication messages was as the howto, but when I try to check it
out from windows administration programs it doesn't work, it's not even
seen in the PrimaryDC DNS. The internal dns in the secondary DC works well,
but not in the opposite direction.
How do I fix this?