DDNS and allow-update declarations

[Nicholas F Miller]

I have a couple of questions regarding how a Microsoft domain  
controller updates a dynamic zone.

1 ) When a domain controller tries to update the zone does it try the  
DNS servers it has listed in its network settings or does it follow  
the SOA for the zone?

2) In the configs below does the slave server's IP need to be listed  
in the allow-update declaration on the master zone server?

Master Server - 1.2.3.4

zone "actived.example.com" {
         type master;
         file "named.ad";
         allow-update {
		1.2.3.4;   	// master DNS server
                 11.22.33.44;         // domain controller 1
                 55.66.77.88.99;         // domain controller 2
                 };
         allow-transfer {
                 5.6.7.8 // slave DNS server;
                 };
};

Slave Server - 5.6.7.8

zone "actived.example.com" {
         type slave;
         file "named.ad";
         allow-update-forwarding {
                 11.22.33.44;         // domain controller 1
                 55.66.77.88.99;         // domain controller 2
                 };
         allow-transfer { none; };
         masters {
                 1.2.3.4 // master DNS server
         };
};

Thanks,
________________________________________________________
Nicholas Miller, ITS, University of Colorado at Boulder