Infrastructure
· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.FIPv6 ReadinessActionIPv6 records exist but unreachableFIX
Having AAAA records but an unreachable server is worse than no AAAA — clients may experience delays before falling back to IPv4.
Advertising IPv6 (AAAA records) without a reachable server means IPv6-preferring clients silently fail every connection.
Learn more ▾ ▴
Modern browsers prefer IPv6 if AAAA exists (Happy Eyeballs algorithm). If the IPv6 server isn't reachable, browsers fall back to IPv4 — but with seconds of added latency per request. Either fix IPv6 reachability or remove the AAAA records.
Source: RFC 8305 (Happy Eyeballs)
DURL VariantsActionwww/non-www, trailing slash, HTTP→HTTPSFIX
www / non-www
Inconsistent — duplicate content risk
HTTP → HTTPS
HTTP version does not redirect to HTTPS
BTLS Certificate Expiry & Recommendations230 days until leaf cert expires — 4 issues to addressREVIEW
Certificate validity
Recommended actions
- Prefer TLS 1.3 — TLS 1.2 is acceptable but TLS 1.3 removes RSA key exchange and improves latency
- Add includeSubDomains to the HSTS directive
- Add the preload directive and submit to hstspreload.org once max-age + includeSubDomains are in place
- Enable OCSP stapling on your TLS server to remove a CA roundtrip and protect user privacy
A+DNS Records4 A records, 18 ms lookupPASS
| A | 151.101.2.217, 151.101.66.217, 151.101.130.217, 151.101.194.217 |
| AAAA | 2a04:4e42::729, 2a04:4e42:200::729, 2a04:4e42:400::729, 2a04:4e42:600::729 |
| CNAME | — |
| NS | ns.isc.afilias-nst.info, ns1.isc.org, ns2.isc.org, ns3.isc.org, nsp.dnsnode.net |
| MX | 5 mx.pao1.isc.org 10 mx.ams1.isc.org |
| TXT | F8C4EB9011 MS=2583E0E0DCCBF33EC6DAFF0B4BFBAF78FFCF7AD0 google-site-verification=6v652rgkk_kI6Ky32iGdxqXjQ4_BAd5DYKsrnRXKUiE google-site-verification=grXE1SbXWNed6C5yQgI8fwxgucE0DppnbICbhZr9qG0 google-site-verification=wg4m8dWi3XVPRYmtBoy6xSKp3juhxIWa6UdxjZkNQCg _globalsign-domain-verification=ckxXdoIq27XGYE4ATbBYQOBeV7PTJWRxYe-PXDyzMX SPF v=spf1 a mx ip4:149.20.0.0/20 ip6:2001:04F8::0/32 ip6:2001:500:60::65/128 ip4:19... |
| CAA | Lookup not available with standard resolver |
CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.
Informational: CAA (Certification Authority Authorization) records weren't checked in this scan.
ARedirect Chain1 redirect(s), 56 ms totalPASS
https://isc.org
24 ms · HTTP/1.1
https://www.isc.org/
33 ms · HTTP/1.1 FINAL
| # | URL | Status | Time | Protocol | Server |
|---|---|---|---|---|---|
| 1 | https://isc.org | 301 | 24 ms | HTTP/1.1 | Varnish |
| 2 | https://www.isc.org/ | 200 | 33 ms | HTTP/1.1 | Apache |
See the visual redirect chain in the HTTP Probe tab →
A+Crawlabilityrobots.txt present, sitemap with 578 URLsPASS
Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.
robots.txt omits Sitemap: directive — crawlers must fetch /sitemap.xml by convention; reliable but missing the explicit hint.
Source: sitemaps.org
User-agent: *
Disallow: /thankyou-contact/
Noindex: /thankyou-contact/
A+Domain Intelligenceisc.org — via Tucows Domains Inc., 32 years, 6 months old, hosted on FastlyPASS
630 days
April 5, 2028
230 days
Issued by GlobalSign nv-sa
32 years, 6 months
Registered April 4, 1994
Enabled
Protects against DNS spoofing
Fastly
ASN AS54113
151.101.194.217
Tucows Domains Inc.
Expiry timeline
Recommended actions
- Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
The domain can be transferred without an unlock step. Enable registrar lock (clientTransferProhibited) in your registrar's control panel to protect against unauthorized or accidental transfers.
Without registrar lock, an attacker who phishes your registrar credentials can transfer the domain in minutes — total brand hijack.
Learn more ▾ ▴
Registrar lock (clientTransferProhibited, clientUpdateProhibited, clientDeleteProhibited) requires extra verification before any transfer/update/delete. Every major registrar offers it free. Combined with 2FA on your registrar account, it's the strongest defense against domain hijacking.
Source: ICANN / domain-security best practice