How do we test our DNS credentials are still valid?

[gregcorbett]

It is currently not know how we can test the DNS failover mechanism, without trying to use it (i.e. Is it possible to validate that our credentials are still valid without attempting a change in the DNS entry).

Even changing the TTL of the DNS entry seems to delete and then add the entry.

Granted, according to RFC2136 section 3.3.2 and 3.4.2.1 - the change is atomic. So maybe deleting and adding the entry is an acceptable test.