[gumby]

> Caches rely on the TTL of records in your zone, or the SOA negative TTL field for negative answers.

Sadly the word "should" ought to have appeared in your sentence.

A lot of resolvers ignore the TTL, either because of the number of misconfigured TTL entries (too short), because they resolve a LOT of names and figure they can't afford to keep looking up certain names, or out of sheer orneryness.

I don't update frequently so when I do plan to make updates I adjust my TTL to a short period, wait a few days, then make the updates, then after a week turn the TTL way up again. I've noticed that this is pointless with some big sites.

[fanf2]

The reason I set my TTLs to 1 hour is to avoid the faff with preparing for a change by fiddling with TTLs. It’s much easier to have a moderate TTL that’s OK for normal use, and not too long to make changes painful.