"Introduced in BIND version 8 and refined in BIND version 9, the
nsupdate provides the system administrator or casual user with a
quick and painless method of updating a DNS zone, adding or
deleting any type of DNS record the name server supports.
"This article describes how to setup dynamic DNS, and provides
some examples of use. For Fedora Core (and Red Hat) users, you will
need to install both the bind (for dnssec-keygen) and bind-utils
(for nsupdate) packages..."