# DNS change propagation outage: first 30 minutes checklist

Source: https://releasefailures.com/incidents/dns-change-propagation-outage/
Content version: 1.0.0
Verified on: 2026-10-21
Licence: CC BY 4.0

Definition: A DNS or load balancer change sends traffic to the wrong target or nowhere.
- [ ] FM-01 Resolve the failing hostname through several public and validating resolvers and record which ones fail and with which error.
- [ ] FM-02 Compare the current DNS records and load balancer target hosts with the last known good state.
- [ ] FM-03 Check whether an infrastructure apply is still running, because records it removed may return when the apply finishes.
- [ ] FM-04 Before rolling back a DNSSEC change, check whether resolvers have cached the DS record, because removing signing then can turn partial errors into SERVFAIL.
- [ ] FM-05 If a load balancer change routes traffic to the wrong host, correct the target or roll back the update and freeze further changes in that area.
- [ ] FM-06 After routing is fixed, drain queued CI workflow runs and watch queue delay return to normal.
- [ ] FM-07 Post a status update naming the affected hostnames and stating that local DNS caches may extend the outage for some users.
- [ ] FM-08 Ask large ISPs and public resolver operators to flush cached records when a cached DNS answer keeps failing after the fix.