Can a DNS checker force caches to update?

No. A checker can observe resolver answers but cannot expire a cache controlled by another network.

Should every resolver return the same result?

Not always. Cached changes, CDNs and geographic traffic management can produce different valid answers.

DNS tools for developers, administrators & everyone who manages a domain 200+ DNS endpoints · No signup

Compare A and CNAME records, understand when to use each, and avoid common DNS configuration mistakes.