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

[Trevor Cordes]

On 2016-04-06 Robert Keizer wrote:
> Why don't you use dig+grep+sed in bash?

Ya, that's one of the ideas (dig).  It looks like dig will
differentiate between named down, vs blocked 53, vs simple invalid
domain.

I'm trying to see if there are other ways also, perhaps ones that don't
require a fork.  And the dig will send out real queries to real
servers, but I guess it will be tempered by the cache?  I'll have to
test what dig does in the different failure modes when a) resolving a
domain that isn't cached vs b) resolving one that is cached.