Test results for: https://stackoverflow.com
DNS (IPv6 NS)
PASS
Hostname stackoverflow.com does have IPv6-addressed nameservers defined.
DNS (IPv6 TLD NS)
PASS
Hostname top-level domain (com.) does have IPv6-addressed nameservers defined.
DNS (IPv4 A Record)
PASS
Hostname stackoverflow.com does have an IPv4 A record (104.18.32.7, 172.64.155.249).
DNS (IPv6 AAAA Record)
FAIL
Hostname does not have IPv6 AAAA record.
DNS (MX Record)
PASS
Hostname stackoverflow.com has at least one MX with AAAA record (2404:6800:4003:c06::1b, 2404:6800:4008:c01::1a, 2607:f8b0:400e:c17::1a, 2607:f8b0:4023:1c05::1a, 2a00:1450:4025:c03::1a).
DNS (Glue)
PASS
Glue does not appear to be needed; nameserver configuration for stackoverflow.com is not self-referencing.
IPv4 Connectivity
PASS
Successfully connected to stackoverflow.com on port 443 over IPv4.
IPv6 Connectivity
FAIL
Could not connect to stackoverflow.com on port 443 over IPv6.
IPv4 Literals
WARN
Could not establish connection to URL https://stackoverflow.com.