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Intermittent empty DNS answers on Route 53 geolocation routing since mid-June (France), anyone else?

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We run geolocation-routed records on Route 53 (continent-level records pointing to regional ALBs).

Confession: we had no Default record for about 6 months. Yes, it's a documented misconfiguration, queries from resolvers that Route 53 can't geolocate get a NOERROR/empty answer. But for 6 months it never caused a single noticeable issue. Presumably a few silent errors we never saw.

Since mid-June 2026 we've been flooded with customer reports: a lot of users unable to reach our API for 5 to 10 minutes, then everything recovers on its own. Nothing in nginx, nothing in the API, nothing in WAF, nothing in ALB access logs, we went down to VPC flow logs. The requests never reached AWS at all.

We eventually correlated it: affected resolvers were getting empty answers and negative-caching them (5 to 10 min depending on their cap), so every client behind that resolver went dark until expiry. Both names we geo-route died in a staggered fashion matching their TTL cycles, while a non-geo-routed name on the same infra never blipped once. Classic missing-Default footgun, amplified by negative caching.

We added the Default record and we've had zero reports since. But we don't have full closure. Why did a 6-month-old misconfiguration suddenly become a weekly fire in mid-June? Our best theory is geo database drift. MaxMind (which AWS references for geolocation (to be confirmed)) shipped several network reclassification waves in May and June, including one on June 24, which is the exact day our reports started. French ISP/mobile resolver egress ranges becoming unmappable would produce exactly this.

The part that still puzzles us: this is a mobile web app, mostly used over 4G/5G. The reports came from many different users, on distinct mobile networks, sometimes at the same time. And every single report came from France. Our records serve the same answer to the whole of Europe and we have users in other countries & continents, yet not one report from outside France. A single poisoned ISP resolver can explain one venue or one household going dark, but simultaneous reports across different French carriers, and only French ones, is harder to explain, unless several French carrier resolver ranges got reclassified in the same data update. That's the main reason we're not fully confident we found the whole story.

Questions:

  1. Has anyone else seen intermittent geo-routing resolution failures since mid-June, especially from French/EU ISPs (Free, Orange, SFR, Bouygues)?
  2. Has anyone gotten AWS to confirm when and how the geolocation data behind Route 53 gets updated?

asked 9 days ago38 views

1 Answer
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Based on your description, your analysis appears sound. The intermittent empty DNS answers you experienced are consistent with the documented behavior of geolocation routing when no default record exists. When Route 53 receives queries from IP addresses it cannot map to geographic locations, it returns a "no answer" response if no default record is configured.

The timing correlation you've identified—sudden issues appearing in mid-June after months of stable operation—strongly suggests changes in how IP addresses are being mapped to locations. Geolocation routing works by mapping IP addresses to locations, and some IP addresses aren't consistently mapped to geographic regions. If resolver IP addresses used by French mobile carriers were reclassified or became unmappable during geolocation database updates, this would produce exactly the pattern you observed: queries from those resolvers would fail to match any of your continent-level records, receive empty answers, and then be negative-cached.

The concentration of reports from France across multiple carriers could indeed indicate that several French ISP resolver ranges were affected by the same geolocation data changes. Mobile networks often use centralized DNS resolver infrastructure, so changes affecting those resolver IP ranges would impact many users simultaneously across different geographic areas.

For intermittent resolution issues like these, the recommended troubleshooting steps include checking association status, reviewing DNS query logs for error patterns, and verifying network connectivity. However, in your case, the root cause was the missing default record combined with geolocation mapping changes.

Your solution—adding the default record—is the correct approach and aligns with best practices for geolocation routing. The default record handles both queries from unmapped IP addresses and queries from locations without specific geolocation records.

Regarding geolocation data updates, Route 53 uses EDNS0 to estimate user location, but specific details about update schedules and data sources are not publicly documented in the available information. For definitive answers about geolocation data update timing and sources, you would need to reach out through the AWS Support Center at https://console.aws.amazon.com/support/ to add correspondence to your existing case or open a new technical inquiry.
Sources
Geolocation routing - Amazon Route 53
Diagnose DNS connectivity issues with Route 53 Global Resolver - Amazon Route 53

answered 9 days ago

EXPERT

reviewed 9 days ago

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