IPv6 health check results

This test checks that the nameservers for your domain have IPv6 addresses.

A full pass requires at least two IPv6 nameservers. A single nameserver will result in a warning.

This check sends a test DNS query to to each of the IPv6 addresses obtained in the first test to confirm that the nameservers are listening on the listed addresses

This test is skipped if no addresses are found in the first test.

Attempts to obtain an IPv6 address for www.yourdomain.

Attempts to obtain an IPv6 address for the specified domain. This is used when users access your website without adding a "www" prefix.

Establishes a connection to your webserver on the IPv6 addresses found in the "IPv6 addresses" tests. By default this will test the www subdomain and fallback to the bare domain.

Establishes a connection to your webserver on the same address and hostname tested in the "Web server IPv6 connectivity" test.

Checks that the mail servers listed in your MX records have IPv6 addresses.

This test will pass if at least one of the listed MX servers has an IPv6 address.

Checks that the mail servers found in the previous test are accepting SMTP connections on their IPv6 address.

This test waits for the remote server to display an SMTP banner. Some mail servers use a delay before displaying such a banner which can slow this test down, or in some cases cause it to time out.

Checks that any IPv6 addresses found for your incoming mail servers have working reverse DNS for those addresses.

Missing reverse DNS is only classed as a warning as reverse DNS is of more importance for outgoing servers, but there is no reliable way to automatically find the outgoing servers used for a particular domain.

Checks that any SPF records for your domain have appropriate IPv6 counterparts. Specifically, any MX records referenced must include at least one server with an IPv6 address, and if any explicit IPv4 ranges are included, then there must be at least one IPv6 range included too.

If your domain does not provide any SPF records, this test will pass.

Checks that all of the zones in the delegation chain between the root nameservers and your zone have working IPv6 for their nameservers, and sufficient glue to find them.

For a full pass, there must be at least two working IPv6 servers at each step in the chain.

If at any step IPv6 addresses for fewer than two nameservers are provided by glue, then the check will result in a warning unless all listed nameservers have IPv6 addresses. This is because otherwise, a resolver may waste time attempting to resolve nameservers that don't have IPv6 addresses.