Reverse DNS for eyeballs?

Fri Apr 21 09:38:29 UTC 2023

I have a feeling that I might be stepping into a can of worms by asking
this,  but..

What's the current thinking around reverse DNS on IPs used by typical
residential/ small business customers.

Way way back in the day I used to generate "filler" reverse dns for all of
these ranges ..  that is, records like "45.100.51.198.in-addr.arpa IN PTR
198-51-100‐45.dialup.example.com", and then add a forward A record to
match.   We had a procedure to override this generic domain upon customer
request when a static IP was assigned, such as for a mail server.

As time has marched on, and other people were responsible for the reverse
dns zones,  cruft from old customers no longer with us has accumulated in
the reverse DNS override file  and I recently discovered that many newer
ranges are either nonexistent or not updated.  As I'm in the process of
cleaning up several other related messes, I'm feeling I should clean this
one up too.

I've kinda felt for a while now that reverse dns isn't really needed for
the customer IPs but before I dump the whole thing overboard and switch to
returning NXDOMAIN unless the customer really needs a reverse dns record I
figured I'd ask what the current thinking is for these among the internet
community.

I'm not talking about reverse dns for  infrastructure/router IPs here,  as
I still feel those need to be kept up to date.  This is just for the
individual end user IPs.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.nanog.org/pipermail/nanog/attachments/20230421/531efcac/attachment.html>