DNS AAAA Record - IPv6 Address Lookup in DNS Messages
A DNS AAAA record maps a domain name to an IPv6 address. It is the IPv6 counterpart to the A record, which maps a name to an IPv4 address.
Key Takeaways
AAAA records return IPv6 addresses.
A records return IPv4 addresses.
DNS queries identify record type in the question section.
AAAA answers include 16 bytes of IPv6 address data.
What AAAA records do
AAAA records let clients find IPv6 addresses for a domain name. A dual-stack domain often has both A and AAAA records so clients can connect over IPv4 or IPv6.
AAAA in DNS packet format
In a DNS query, the question section contains the domain name, query type, and class. For AAAA, the query type indicates IPv6 address lookup. Responses include resource records with 16-byte IPv6 addresses.
How to analyze AAAA traffic
Check whether the packet is a query or response, inspect the question type, then read the answer section. Compare answer count, TTL, and returned IPv6 addresses to understand resolution behavior.
Practical Reference
| Item | Value | Analysis Note |
|---|---|---|
| AAAA | IPv6 address record | Returns 128-bit addresses. |
| A | IPv4 address record | Returns 32-bit addresses. |
| Question type | Record requested | Appears in DNS question section. |
| Answer data | Address bytes | AAAA RDATA is 16 bytes. |
FAQ
Why is it called AAAA?
An IPv6 address is four times as long as an IPv4 address, so the record name extends the A-record naming pattern.
Can a domain have both A and AAAA records?
Yes. That is common for dual-stack services that support both IPv4 and IPv6.