What happened
On 2026-06-26, every ClouDNS Premium anycast nameserver for my zones and my friend’s zone experienced a major outage – periodic timeouts on UDP/53 within a ~20-minute window:
~12:39 UTC (21:39 JST) — first symptom: my friend’s domain failed to resolve due to a DNS timeout (;; communications error to <ip>#53: timed out), as his NS vanities point to pns41–44.
~12:44 UTC (21:44 JST) — reproduced directly against my own zones (pns1–4).
~12:59 UTC (21:59 JST) — last observation; recovered on its own shortly after.
IPs in Premium Anycast timed out, plus the standard ns3. The standard ns1/ns2/ns4 answered normally throughout. (However, note that ns1 is a problematic server, as I mentioned in my past article, and I do not recommend using it as the +1.)
Four groups of anycast nameservers, yet somehow they provide no redundancy between one another. BGP misconfiguration? A bad rollout? There’s no way to tell, as there’s zero public statement from ClouDNS themselves – support ticket only confirmed a “temporary technical situation” in their reply, with zero detail about what went wrong, and they don’t have a status page as far as I know.
The fix: 3+1 (or 4+1 if you prefer)
Replace one of the four anycast nodes with one of ClouDNS’s standard (unicast) nameservers. Three premium anycast for speed, one standard unicast on a separate network as insurance.
Test a few standard nameservers directly and pick one that’s both well-routed from your audience and on a different network from the anycast fleet:
dig @<ip> yourdomain SOA +norecurse # authoritative? same serial?With this setup, when the anycast set goes quiet again, your domain stays up.