OT: RBL for dynamic "no reverse DNS" lookups

[Rob McEwen <ro...@powerviewsystems.com>]

OT: RBL for dynamic "no reverse DNS" lookups

I'm trying to find an RBL which will return a standard RBL return code (like
"127.0.0.2") if/when the IP passed to the RBL doesn't have a reverse DNS
entry.

(1) I know that SA doesn't have a need for this as another function is
already available in SA for this. But I need this for a **different**
utility, not SA (which is why I said, "OT").

(2) This other utility doesn't have the option to check for "no reverse
DNS", but CAN do whatever general RBL lookups I tell it to do. Also, I don't
have access to this utility's source code.  However, if I can find this kind
of RBL I mentioned, then I can use this utility's RBL lookups against that
kind of RBL to accomplish checking a message's sending server for "no
reverse DNS". But, again, doing lookups on (reversedIP).in-addr.arpa is NOT
an option in this utility because it **only** works with the traditional RBL
responses, which are always numeric, unlike reverse DNS lookups.

(3) I know that some aggressive RBLs factor in "no reverse DNS"... but,
instead, I'm looking for an RBL which would do a DYNAMIC lookup to see if
there is "no reverse DNS", even if that RBL hasn't checked that IP before or
hasn't previously added that IP to it's "no reverse DNS" nameserver
database.

(4) And, of course, I understand that it is NOT a good idea to block
**solely** due to a sending server's IP not having a reverse DNS lookup.
Rather, I'm using this for auditing, testing, and other things.

Thanks,

Rob McEwen
PowerView Systems