Hi Paul,
Seems strange that a planned change would lead to a call to clear caches.
Is there some client behaviour you're seeing that suggests that some caches
are holding onto old data for too long? Or was there some unexpected
complication in your delegation changes?
Are the zones that were being served from the old nameservers meaningfully
different from the zones being served from the new ones?
It might be helpful to illustrate good and bad behaviour (in terms of DNS
responses) to avoid unnecessary cache-clearing. An empty cache is a sad
cache.
Joe
On Aug 9, 2015, at 18:11, paul tinson