Some DNS recursive resolvers have longer-than-desired round-trip times to the
closest DNS root server. Some DNS recursive resolver operators want to prevent
snooping of requests sent to DNS root servers by third parties. Such resolvers can
greatly decrease the round-trip time and prevent observation of requests by running
a copy of the full root zone on a loopback address (such as 127.0.0.1). This
document shows how to start and maintain such a copy of the root zone that does not
pose a threat to other users of the DNS, at the cost of adding some operational
fragility for the operator.