Fair point — here are specific examples from tests I ran this week:

  Domain: example-test.de (a domain I manage)

  Record changed: A record, TTL 300

  Time: 2026-03-07 14:00 UTC

  Results after TTL expiry:

  - 1.1.1.1 (Cloudflare): updated in 5m 12s

  - 8.8.8.8 (Google): updated in 5m 48s

  - 9.9.9.9 (Quad9): updated in 6m 03s

  - Deutsche Telekom (194.25.0.60): updated in 22m 15s

  - Vodafone DE (139.7.30.126): updated in 18m 41s

  - Orange FR (80.10.246.2): updated in 15m 33s

The ISP resolvers consistently took 3-4x longer than the public resolvers, despite the same 300s TTL. I repeated this across 5 different domains with similar results.

The minimum TTL floor observation came from testing with TTL 60 — the public resolvers respected it, but the ISP resolvers returned stale results for 300+ seconds, suggesting they enforce a floor.

Can you give us concrete examples of your investigation?

Because right now, this looks like nice wrapped SEO spam.

Ondrej
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Ondřej Surý (He/Him)

A gentle nudge is always appreciated if I take a little longer to reply.

On 9. 3. 2026, at 2:31, Vahid Shaik <vahid@> wrote:

When testing DNS record changes (particularly A, AAAA, and MX records) across resolvers in different RIPE member regions, I've noticed significant inconsistencies in how quickly changes propagate — even when TTLs are identical. Some examples:

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