What are some of the shortcomings of DNS?

What will be an ideal response?

Despite DNS' robust capabilities and its many advantages, it does suffer from some shortcomings. Chief among these is that DNS database updates normally require that a qualified administrator-one with the proper knowledge and necessary access rights to the zone files-operates directly on the DNS database files, or uses special-purpose tools (such as Nsupdate in the UNIX environment) to make changes. The requirement that DNS databases be edited makes it a chore to manage updates.
Another problem to which DNS falls prey might be called "propagation delay,"which relates to the amount of time it takes for cached values to catch up with changes to authoritative databases after changes are made to those "master copies" of DNS records. This explains why service providers routinely warn their customers that it might take as long as three days for a name-to-address translation to become completely effective on the Internet, as when transferring a domain name from one provider to another (which invariably means changing the underlying IP address associated with that domain name).