Implemented filtering of exported subdomains

src/hostinfo/named.py

@@ -129,6 +129,8 @@ def header(tree, domain, origin=None):
         pass
     delegation = []
     for ns in tree._host_._interface_._nameserver_:
+        if ns.external[0] != 'yes':
+            continue
         subdomain = ns.domain[0].split('.')
         if subdomain[1:] == domain.split('.'):
             delegation.append( '%-16sIN      NS     %s' %