Questions about DNS & Bind book

[Chris]

Hi all,

I've just started reading the World Famous O'Reilly Book. I'm pretty
pleased so far (don't hurt me, but I usually don't care for O'Reilly
books, and it took me a while to cave in and buy this one). I'm
actually enjoying reading about DNS! I just have a couple of questions
.. . .

On page 68, I see the sentence "named.root is the same file we've been
calling db.cache". I gulped, because to that point I hadn't seen
db.cache referenced, though it's mentioned several times later. After
some panicky rereads, I still didn't find where db.cache was
originally mentioned (I'm sure it was there, but computers have
destroyed my ability to scan text manually, to mix metaphors), but I
did come to th conclusion that db.cache is just the plain ole
named.root file by another name, and that there's nothing magical
about the name, except that since the book us prepending all RR files
with db., it figured it might as well be consistent.

Is there more to it than that? I certainly don't want to be in the
dark on db.cache.

Also, I read the part on configuring Bind for reverse DNS. What I'd
like to know is. is Reverse-DNS necessary? I have an ADSL connection
and 5 static IPs, so right now my ISP does my reverse DNS. Since doing
my own reverse DNS require my ISPs cooperation (as well as some
non-octet boundary stuff I've read the RFC on but don't fully
understand), I'd like to put off doing it for a while if there's no
harm.

Thanks,
Chris