Bind, rpz and TXT/MX records

Emanuele Santoro manu at
Sat May 23 11:34:38 UTC 2020

Hello there!

I'm trying to use rpz functionalities from bind to overlay some local
dns entries onto a public dns zone.

The problem is that while this works okay for regular records
(A/AAAA/CNAME) this blocks other record type requests (mainly TXT/MX).
I say "blocks" as in "it has no local data for such kind of records and
thus will respond with NODATA/NXDOMAIN".

Has anyone faced this problem before ? Any hints or suggestions ?

Thanks in advance,
Emanuele Santoro

p.s: I have read the rpz spec and the bind documentation, plus various
webpages here and there. There are many policy triggers (RPZ-CLIENT-IP,
QNAME, RPZ-IP, RPZ-NSIP) to differentiate the requests in order to have
different behaviors in different situation.

Something like a QTYPE policy trigger (query type, as in MX or TXT or A
or other) would be ideal, so that it would be possible to write
something like:

    ; let txt queries pass through        CNAME    rpz-passthru.

    ; block mx queries        CNAME    *.

Also: the dns-rpz spec at
specifies a specific action override:
LOCAL-DATA-OR-PASSTHRU. I haven't found any reference about this in the
bind documentation. Did I miss something ?

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