Index: trunk/packages/sipb-xen-dns/code/dnsserver.py
===================================================================
--- trunk/packages/sipb-xen-dns/code/dnsserver.py	(revision 912)
+++ trunk/packages/sipb-xen-dns/code/dnsserver.py	(revision 913)
@@ -86,4 +86,10 @@
                                                 ttl, self.soa, auth=True))
             else:
+                if 'passup' in dir(config.dns) and host in config.dns.passup:
+                    record = dns.Record_CNAME('%s.%s' % (host, config.dns.parent), ttl)
+                    return defer.succeed((
+                        [dns.RRHeader(name, dns.CNAME, dns.IN, ttl, record, auth=True)],
+                        [], []))
+
                 if host:
                     value = invirt.database.Machine.get_by(name=host)