The DNS Incremental Transfer, Notification, and Dynamic Update Working
Group is concerned with three areas of future DNS protocol
development:

 1. Incremental Zone Transfer - As the sizes of some zone files have 
grown
    quite large, it is believed that a protocol addition to allow the
    transfer of only the changed subset of a zone will reduce net 
traffic
    and the load on critical servers.
 
 2. Change Notification - There can be large time intervals during which
    at least one secondary has data that is inconsistent with the 
primary.
    The proposed ``notify'' mechanism (where the primary sends a message
    to known secondaries) facilitates fast convergence of servers
    vis-a-vis consistency of data in the zones.
 
 3. Dynamic Update - The need to frequently update small portions of a
    large zone and to have those updates propagate is perceived.