Maintained by: NLnet Labs

message is bogus, non secure rrset with Unbound as local caching resolver

Tony Finch
Thu Mar 3 12:43:30 CET 2016


Havard Eidnes <he at uninett.no> wrote:
>
> > CD=1 is the wrong thing when querying a forwarder. When a
> > domain is partly broken, queries that work with CD=0 can be
> > forced to fail with CD=1.
>
> Relly?  I interpreted the use of CD=1 as "I want to do my own
> DNSSEC validation, and therefore don't want or need the
> validation service which could be provided by the forwarder",
> especially as noted above when the communication isn't secured.
> It should not make much of a difference wrt. the validity of the
> end result whether the forwarder or the unbound resolver does the
> DNSSEC validation?

This current case is a perfect example: unbound works when it queries
upstream with CD=0 but not with CD=1.

If a domain is a bit broken then you can get bogus data into the upstream
cache using CD=1 and subsequent CD=1 queries will receive the bogus data.
If the downstream validator doesn't have an alternative resolution path it
is now stuck. But if it queries with CD=0 it can get unstuck.

You need to suppress bogus data at every point in the resolution path.

https://www.ietf.org/mail-archive/web/dnsop/current/msg11512.html

Tony.
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