{"kind":"host","input":"cdc.gov","report":{"host":"cdc.gov","checkedAt":"2026-10-31T08:12:16.751Z","a":{"status":"found","values":["23.212.250.4","23.212.250.6"],"ttl":20,"via":"Cloudflare","cname":[]},"aaaa":{"status":"found","values":["2600:1408:c400:11::17cd:6b56","2600:1408:c400:11::17cd:6b44"],"ttl":20,"via":"Cloudflare","cname":[]},"verdict":"dual-stack","www":{"host":"www.cdc.gov","a":{"status":"found","values":["23.49.180.79"],"ttl":41,"via":"Cloudflare","cname":[]},"aaaa":{"status":"found","values":["2600:1408:c400:784::2461","2600:1408:c400:78c::2461"],"ttl":20,"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":"cdc.gov has 2 IPv6 addresses and answers on every one we tested.","addresses":[{"address":"2600:1408:c400:11::17cd:6b56","result":"answers","port":443},{"address":"2600:1408:c400:11::17cd:6b44","result":"answers","port":443}]},{"key":"www","label":"www over IPv6","status":"pass","detail":"www.cdc.gov has 2 IPv6 addresses and answers on every one we tested.","addresses":[{"address":"2600:1408:c400:784::2461","result":"answers","port":443},{"address":"2600:1408:c400:78c::2461","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":"primary.us.etp.fireeyegov.com","ipv6":false},{"host":"alt1.us.etp.fireeyegov.com","ipv6":false},{"host":"alt2.us.etp.fireeyegov.com","ipv6":false},{"host":"alt3.us.etp.fireeyegov.com","ipv6":false}]},{"key":"dns","label":"Nameservers have IPv6","status":"pass","detail":"6 of 6 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up.","hosts":[{"host":"a5-66.akam.net","ipv6":true},{"host":"a28-65.akam.net","ipv6":true},{"host":"a8-67.akam.net","ipv6":true},{"host":"a1-43.akam.net","ipv6":true},{"host":"a2-64.akam.net","ipv6":true},{"host":"a9-64.akam.net","ipv6":true}]}]},"https":{"status":"pass","summary":"Loads over IPv6 with a valid certificate after 2 redirects: HTTP 200.","hops":[{"url":"https://cdc.gov/","address":"2600:1408:c400:11::17cd:6b56","status":301,"tls":"valid"},{"url":"https://www.cdc.gov/","address":"2600:1408:c400:784::2461","status":301,"tls":"valid"},{"url":"https://www.cdc.gov/index.html","address":"2600:1408:c400:784::2461","status":200,"tls":"valid"}]},"receiptId":"WbDIze7YfW"}