You can run Simple DNS Plus and take advantage of DNS
caching no matter what type of Internet connection you are using
(even dial-up).
In order to host domain names with your own DNS
server, you need an IP address which doesn't change (or changes very
seldom).
Many cable/DSL Internet providers do assign IP addresses
dynamically, but in most cases this does not mean that your IP
changes - you just get the same IP address assigned over and over
again.
So for all intents and purposes the IP address is static -
and is perfect for running a DNS server hosting domain names.
To
make sure that your IP address doesn't change, you probably need to
monitor this for at least 10 days (or contact your connection
provider).