A / AAAA Lookup
Find IPv4 and IPv6 addresses for any domain
Fast DNS resolution for A and AAAA records
Type a domain to check A (IPv4) and AAAA (IPv6) records.
What is an A record?
An A record maps a domain to an IPv4 address. It tells browsers and devices where to connect when they request a website or service.
Most websites publish at least one A record so they can be reached on IPv4 networks.
What is an AAAA record?
An AAAA record maps a domain to an IPv6 address. IPv6 is the modern successor to IPv4 and provides a much larger address space.
Publishing AAAA records enables faster routing and accessibility on IPv6 networks.
DNS A and AAAA records explained
AAAA records store IPv6 addresses (for example, 2001:db8::1), while A records store IPv4 addresses (for example, 192.0.2.34). A domain can publish one or both record types depending on its network support.
When both A and AAAA records exist, most clients prefer IPv6 and fall back to IPv4 if IPv6 is not available. If a domain only has A records, IPv6-only networks will not be able to reach it.
Need domain ownership details? Use the WHOIS lookup to see registrar and registration dates.
Example AAAA record
A typical AAAA record includes the host label, record type, IPv6 value, and TTL in seconds.
| Record | Type | Value | TTL |
|---|---|---|---|
| www | AAAA | 2001:db8::1 | 3600 |
www is the record label. Use @ for the root.
AAAA is the record type for IPv6.
2001:db8::1 is the IPv6 address value.
3600 is the TTL (1 hour). Caches keep the record for this duration.
Multiple records
It is normal to see multiple A or AAAA records. DNS responses can rotate between them, which helps distribute traffic, improve availability, and support regional routing.
TTL and propagation
TTL controls how long resolvers cache a record. Lower TTL values propagate updates faster, while higher TTL values reduce query load. After changes, it can take up to the TTL time for caches to refresh.
Error glossary
NXDOMAIN
The domain does not exist in DNS. Check the spelling or verify the domain is registered.
Check WHOIS lookupSERVFAIL
The resolver failed to answer. This can be caused by DNSSEC issues, upstream outages, or misconfiguration.
Run DNSSEC checkTimeout
The DNS server did not respond in time. Try again or check network connectivity and DNS health.
Check query latencyWhy Use CuscusLab A/AAAA Lookup?
Dual Stack Coverage
Check IPv4 and IPv6 results side by side to confirm full network reachability.
Fast DNS Resolution
Live lookups return current records without relying on stale cached results.
Troubleshooting Ready
Verify CDN, load balancer, or hosting targets when diagnosing connectivity issues.
Frequently Asked Questions
What is the difference between A and AAAA records?
A records map a domain to an IPv4 address, while AAAA records map a domain to an IPv6 address. IPv6 is the newer protocol designed to provide a larger address space.
Why do I see multiple IP addresses?
Multiple A or AAAA records are common. They support load balancing, geographic routing, and redundancy for CDNs and large hosting providers.
What if no AAAA record is returned?
That usually means the domain does not publish IPv6 addresses. The site can still work over IPv4, but IPv6-only networks will not reach it.
What does TTL mean in DNS records?
TTL stands for Time To Live. It tells resolvers how long they can cache a record before requesting an update. Lower TTL values propagate changes faster but can increase DNS load.