At this point, it's useful to repeat something we said earlier in this book. Calling a given name server a primary master name server or a slave name server is a little silly. Name servers can be -- and usually are -- authoritative for more than one zone. A name server can be a primary master for one zone and a slave for another. Most name servers, however, are either primary master for most of the zones they load or slave for most of the zones they load. So if we call a particular name server a primary master or a slave, we mean that it's the primary master or a slave for most of the zones it loads.