Say I do a dns lookup of a name of mine and the lookup fails as the name is undefined. Then I define it, as a CNAME. Now I go back and do another lookup. I assume my machine’s o/s will cache the negative result, the ‘not found’?
But for how long will the negative caching be in effect, until it then looks it up again and finds it works?
Is there somewhere where you yourself can specify a negative caching result lifetime?