[dns-operations] DNSSEC parameter BCP

[Viktor Dukhovni]

On Mon, Jun 12, 2023 at 10:41:12AM -0400, Viktor Dukhovni wrote:

> On Mon, Jun 12, 2023 at 10:37:22AM -0300, daniel majela wrote:
> 
> > What is the best algorithm for ksk and zsk?
> 
> The BCP algorithm is ECDSAP256SHA256(13).  This is both more secure and
> more compact than RSA.  It is in wide use:
> 
>     https://stats.dnssec-tools.org/
>     https://stats.dnssec-tools.org/#/?dnssec_param_tab=0
> 
> Today, out of 22,010,850 known signed zones, the number with algorithm
> 14 KSKs is 9,982,219 or just over 45%.
> 
> If you choose NSEC3, set the additional iteration count to 0, and avoid
> opt-out unless you're operating a particularly large (10M+ delegations)
> zone that is thinly signed.  An empty salt is also sensible.

I was reminded off-list that I neglected to recommend NSEC as the BCP
default choice for end-user zones.  Much simpler than NSEC3, and again
smaller response sizes.

In addition, best to optimise for "agility": keep your TTLs reasonably
short, rarely more than one hour, and ideally shorter.  That way, if
anything does go wrong, you should be able to recover faster.

You don't currently get to choose (through your registrar) the TTL of
the DS RRs in the parent zone, perhaps some day...  In the mean time,
many registry now default DS TTLs to 1 hour or less.  Some still have
DS TTLs as high as one day.

-- 
    Viktor.