[RndTbl] programatically determine if DNS is down or blocked?

[Trevor Cordes]

On 2016-04-08 Theodore Baschak wrote:
> 
> Have you looked at running multiple recursive resolvers on your
> system and using a load balancer to always hit a live one?
> http://dnsdist.org/

That's an idea... it would take care of named crashing.  But I still
need more to ensure The Big Hosting Provider isn't blocking 53 UDP
in/out of my box at their firewall, or that the whole world's DNS isn't
down / DDoS'd (don't laugh, I've seen a few times where several root
NS's were being DDoS'd).

Thanks for all the ideas guys!