Practices (6)

Configure your BIND9 named as a caching server
do you need a "hint" file of root servers?
Play with it
ask the servers for various names and see what happens
compare the response (cached data vs non-cached data)
browse/manage the cache contents
rndc dumpdb/flush/flushname
what if a queried zone has many lame delegations?
which TTL is used for non-existent names?
e.g. none.wide.ad.jp
resolve that, and see the cached info by rndc dumpdb