--- title: Free AAAA Record Lookup description: Check the IPv6 address a domain publishes — its AAAA records and TTLs. Confirm dual-stack is really on, catch a record that points at an address nobody listens on, and see why IPv6-only clients time out while IPv4 works. canonical: https://watchfor.io/aaaa-record-lookup --- [Back to all free tools](/free-tools) # AAAA Record Lookup Check the IPv6 address a domain publishes — its AAAA records and TTLs. Confirm dual-stack is really on, catch a record that points at an address nobody listens on, and see why IPv6-only clients time out while IPv4 works. Result No result yet Enter the inputs above and press Run. Results appear here in a moment. Monitor this 24/7 — get alerts on the first failure. [Start free](/auth/sign-up) Only run these tools against systems you own or are authorized to test. Using them to scan or probe systems without permission violates our [Terms](/legal/terms). ## What is AAAA Record Lookup ? An AAAA record maps a name to an IPv6 address — the 128-bit kind, written like 2606:4700::6810:84e5 . It is the IPv6 twin of the A record, and the one most teams add last, test least, and get blamed for first: a browser on a mobile network with IPv6 will try the AAAA address before the A address, and if the AAAA record points at something that doesn't answer, that user waits through a timeout while your IPv4-only monitoring says everything is fine. This tool resolves the AAAA records of any name and shows each address with its TTL. Use it to confirm dual-stack is really published, to find the AAAA record that points at an address nobody configured on the server, and to check that the IPv6 side of a migration moved along with the IPv4 side. ## How it works The query is identical to an A lookup with QTYPE=AAAA : - 1 Query the chosen resolver — Public resolvers return AAAA records regardless of whether the querying network has IPv6 — the record type is independent of the transport used to ask. - 2 Chase any CNAME — A www that is a CNAME to a CDN gets its AAAA records from the CDN's name; you see the chain so it's clear whose address you're looking at. - 3 Show the raw answer — Addresses exactly as returned, in compressed notation, with remaining TTL, RCODE and query time. Whether the address actually answers is a separate question — follow up with a ping or port check to the IPv6 address to prove reachability. ## When you'd use it ### Enabling IPv6 for the first time You added the address to the server and the AAAA record to DNS. Look it up: is the record visible, is it the address you meant, does it match the one bound on the host? Then test a connection to it from a probe with IPv6. ### Some users time out, others don't A classic dual-stack failure: the AAAA record points at an address the firewall blocks or the server never got. IPv4 clients are fine; IPv6-capable clients hang for seconds before Happy Eyeballs falls back. Check the AAAA record first. ### After a server move The A record was updated by the person doing the migration; the AAAA record still points at the old host. Half the mobile traffic is now on a server you thought you'd decommissioned. ### Auditing a CDN or hosting change Some providers publish AAAA records automatically, some not at all. Knowing which is true for your setup decides whether you have IPv6 at all. ## Reading the result ### Compressed notation 2606:4700::6810:84e5 is the same address as 2606:4700:0000:0000:0000:0000:6810:84e5 — runs of zero groups collapse to :: once. The IPv6 subnet calculator expands and compresses either way. ### No AAAA record (NOERROR, empty) The name has no IPv6 address published. Clients simply use IPv4. It's the normal state for most of the internet, and a finding only if you expected IPv6. ### Address types Public IPv6 starts with 2 or 3 (global unicast). fe80:: is link-local and fc00::/7 is unique-local — neither belongs in a public AAAA record. ### Different TTLs on A and AAAA The two records are independent; a change to one doesn't touch the other's TTL. A mismatch after a migration usually means only one of them was edited. ## Check it yourself dig AAAA example.com @1.1.1.1 +noall +answer ping6
or curl -6 https://example.com then proves the address answers, which the record alone doesn't. ## Common pitfalls ### Publishing an AAAA record before the server listens on it The moment the record exists, IPv6 clients will use it. Bind the address, open the firewall, test from outside — then publish. ### Monitoring only IPv4 If every check you run resolves the A record, an IPv6 outage is invisible to you and very visible to users. Run at least one monitor with ip6 protocol against the AAAA address. ### A firewall that forgot IPv6 Many security groups and iptables rules are written once for IPv4. The AAAA record is fine, the server listens, and the packets are dropped by a default-deny nobody remembers writing. ## Run AAAA Record Lookup on every change, not just once. Get alerts the moment something breaks — across HTTP, DNS, SSL, RDAP, ping, blacklist and more. Free forever for 10 monitors. No card. [Start free](/auth/sign-up) ## Frequently asked questions Do I need an AAAA record? Not for the site to work — IPv4 still reaches everyone. You need one to be reachable over IPv6, which is now the majority of mobile traffic in many countries, and which avoids carrier-grade NAT on the client side. If you publish one, monitor it. Why does my site have an AAAA record I never created? Your CDN or hosting provider added it, or the www CNAME resolves to a provider name that has one. It's usually correct — the provider handles IPv6 at its edge — but the lookup tells you whose address it is. Can an AAAA record and an A record have different targets? Yes, they're independent records. Some setups deliberately send IPv6 to a different edge. Accidentally, it's the migration-that-moved-one-record problem. Why does the browser prefer IPv6? RFC 6724 address selection and Happy Eyeballs (RFC 8305): a dual-stack client tries IPv6 first and races IPv4 a few hundred milliseconds later. A broken AAAA record costs that delay on every connection. What does :: mean in the address? One run of consecutive all-zero groups, omitted. It can appear only once per address so the expansion is unambiguous. ## Related dns tools - [DNS LookupResolve A, AAAA, MX, TXT, NS, SOA, CNAME, PTR, CAA, SRV records for any domain.](/dns-checker) - [DNS PropagationCheck how a DNS record looks from every prober region simultaneously — spot stale anycast nodes and propagation gaps on a world map.](/dns-propagation-checker) - [Whois LookupModern RDAP-based domain registration lookup: registrar, expiry, nameservers, status flags.](/whois-lookup) - [A Record LookupFind the IPv4 address a domain resolves to — every A record with its TTL, from the resolver of your choice. Spot a stale IP after a migration, a missing record behind a 'site can't be reached', or a round-robin set that is one address short.](/a-record-lookup) --- Canonical page: https://watchfor.io/aaaa-record-lookup · Site guide: https://watchfor.io/llms.txt