Why Does a Website Work With IPv4 but Fail With IPv6?

A site can work over IPv4 while failing over IPv6 if an AAAA record points to the wrong host, the web server is not listening on IPv6, or firewall and certificate settings differ. Some visitors prefer IPv6 automatically.

What to check

Compare A and AAAA answers, test each route, inspect IPv6 firewall and listener configuration, and verify the hostname and certificate on both paths. Review logs to see whether IPv6 requests reach the intended server.

Recommended next step

Correct the IPv6 configuration end to end or remove an incorrect AAAA record if IPv6 is not supported. Retest from an IPv6-capable network and keep DNS consistent across hostnames.

How Informatix Systems can help

Informatix Systems provides DNS, domain, and hosting services. We can review the setup, trace the issue through relevant systems, and help plan a practical correction. Contact us with the platform involved, when the issue began, and non-sensitive error details.