{"kind":"host","input":"4b1u.com","report":{"host":"4b1u.com","checkedAt":"2026-11-12T09:14:31.098Z","a":{"status":"found","values":["104.21.42.57","172.67.201.88"],"ttl":300,"via":"Cloudflare","cname":[]},"aaaa":{"status":"found","values":["2606:4700:3032::6815:2a39","2606:4700:3034::ac43:c958"],"ttl":300,"via":"Cloudflare","cname":[]},"verdict":"dual-stack"},"readiness":{"grade":"B","summary":"Works over IPv6, with one gap: its mail servers lack IPv6.","reachabilityTested":true,"checks":[{"key":"web","label":"Website over IPv6","status":"pass","detail":"4b1u.com has 2 IPv6 addresses and answers on every one we tested.","addresses":[{"address":"2606:4700:3032::6815:2a39","result":"answers","port":443},{"address":"2606:4700:3034::ac43:c958","result":"answers","port":443}]},{"key":"mail","label":"Mail servers (MX) have IPv6","status":"fail","detail":"None of the mail servers has an AAAA record.","hosts":[{"host":"mail.4b1u.com","ipv6":false}]},{"key":"dns","label":"Nameservers have IPv6","status":"pass","detail":"2 of 2 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up.","hosts":[{"host":"rachel.ns.cloudflare.com","ipv6":true},{"host":"sterling.ns.cloudflare.com","ipv6":true}]}]},"https":{"status":"fail","problem":"redirect-no-ipv6","summary":"Redirects to navynavy83126.com, which has no IPv6 address — so IPv6 visitors end up needing IPv4 after all.","hops":[{"url":"https://4b1u.com/","address":"2606:4700:3032::6815:2a39","status":302,"tls":"valid"},{"url":"http://navynavy83126.com/","note":"redirects to navynavy83126.com, which has no IPv6 address"}]},"receiptId":"jFudz5Alrc","reused":true,"measuredAt":"2026-11-12T09:14:31.648Z"}