ctu.int — Caribbean IPv6 Monitor

Score2/4

Overall IPv4-only

Collected2026-10-14 20:33 UTC

Measurement estimates from a single vantage point — not a compliance certification. Guidance below is for operators, not an SLA.

Priority next steps

Publish AAAA records for web host: ctu.int.
Enable DNSSEC signing and publish a DNSKEY at the apex. Use DNSViz to validate the full chain.

Dual-stack

[2] 2/2/2 [O]

Meaning: Shows how many authoritative name servers exist, and how many IPv6 endpoints are configured, responsive, and operational.

IPv4 2/2/2 · IPv6 2/2/2 · location O

Host	IPv4	IPv6	Probes
`ns2.arin.net` [O]	199.71.0.108	2001:500:31::108	ipv4 199.71.0.108 ok; ipv6 2001:500:31::108 ok;
`ns1.arin.net` [O]	199.212.0.108	2001:500:13::108	ipv4 199.212.0.108 ok; ipv6 2001:500:13::108 ok;

Dual-stack

[1 MX] v4 smtp 4/4/4 v6 smtp 4/4/4 [O]

Meaning: Shows MX footprint and SMTP health per IP family. Operational means an SMTP banner and EHLO exchange succeeded on port 25.

IPv4 SMTP 4/4/4 · IPv6 4/4/4 · location O

Host	IPv4	IPv6	Probes
`ctu-int.mail.protection.outlook.com` [O]	52.101.60.182, 52.101.42.87, 52.101.41.28, 52.101.42.81	2a01:111:f403:f909::d, 2a01:111:f403:f801::, 2a01:111:f403:f900::1, 2a01:111:f403:c918::5	ipv4 52.101.60.182 ok; ipv4 52.101.42.87 ok; ipv4 52.101.41.28 ok; ipv4 52.101.42.81 ok; ipv6 2a01:111:f403:f909::d ok; ipv6 2a01:111:f403:f801:: ok; ipv6 2a01:111:f403:f900::1 ok; ipv6 2a01:111:f403:c918::5 ok;

IPv4-only

[1] 0/0/0 [I]

Meaning: Shows IPv6 web endpoint readiness for the discovered HTTPS host. Operational means family-specific HTTPS requests complete successfully.

IPv4 1/1/1 · IPv6 0/0/0 · location I

Host	IPv4	IPv6	Probes
`ctu.int` [I]	64.150.182.42	—	ipv4 ok;

📌 Action item(s):

Unsigned

U/-/-

Meaning: Shows whether DNSKEY data is observed at the apex (signed), absent (unsigned), or unavailable due to lookup error.

Apex DNSKEY presence only — not full chain validation.

📌 Action item(s):

Enable DNSSEC signing and publish a DNSKEY at the apex. Use DNSViz to validate the full chain.

p=reject

p=reject — published organizational policy. Strongest published policy (SPF/DKIM alignment still not measured here).

Meaning: Published DMARC policy at _dmarc.ctu.int (DNS TXT). Shows organizational policy (p=) and subdomain policy (sp=) when set.

Record at _dmarc.ctu.int:

v=DMARC1; p=reject; fo=1:d:s; adkim=s; aspf=s; rua=mailto:rua.dmarcReports@ctu.int; ruf=mailto:ruf.dmarcReports@ctu.int; sp=reject; ri=86400

Policy publication only — SPF/DKIM not measured. Not part of the 0–4 row score.