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Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
88
GRADE
B
FIX
0
REVIEW
4
PASS
5
INFO
0
Probed from Madrid, Spain
200 OK
Checks
9
5 PASS 4 REVIEW
B
DNS Records
4 A records, 25 ms lookup
REVIEW
4 A records, 25 ms lookup
Info::
Resolves to 4 IPv4 address(es)
Got: 151.101.193.55, 151.101.65.55, 151.101.1.55, 151.101.129.55
Info::
Has 4 IPv6 (AAAA) record(s)
Got: 2a04:4e42:600::311, 2a04:4e42:200::311, 2a04:4e42:400::311, 2a04:4e42::311
Warning::
CNAME record at zone apex
A CNAME at the zone apex can break MX and NS records. Use ALIAS/ANAME or A records instead.
Got: dualstack.m.sni.global.fastly.net
Info::
No NS records found
Info::
No MX records — email not configured via DNS
Info::
CAA records not checked
CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.
Info::
No SPF record found in TXT records
SPF helps prevent email spoofing. Add a TXT record starting with 'v=spf1'.
Info::
DNS resolution time: 25 ms
Got: 25 ms
A151.101.193.55, 151.101.65.55, 151.101.1.55, 151.101.129.55
AAAA2a04:4e42:600::311, 2a04:4e42:200::311, 2a04:4e42:400::311, 2a04:4e42::311
CNAMEdualstack.m.sni.global.fastly.net
NS
MX
TXT
CAALookup not available with standard resolver
Resolved in 25 ms

A CNAME at the zone apex can break MX and NS records. Use ALIAS/ANAME or A records instead.

Why this matters

CNAME at the apex (example.com) breaks every other apex record (MX, TXT, NS) — DNS-protocol violation per RFC 1034.

Learn more

RFC 1034 forbids CNAME alongside other records at the same name. Some DNS providers offer ALIAS / ANAME / flattened-CNAME records that work around this — use those instead. Otherwise apex-level CNAME breaks email (no MX), domain ownership verification (no TXT), and more.

Source: RFC 1034

CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.

Why this matters

Informational: CAA (Certification Authority Authorization) records weren't checked in this scan.

SPF helps prevent email spoofing. Add a TXT record starting with 'v=spf1'.

Why this matters

Without SPF, receiving servers can't validate sending IPs — your domain is easier to spoof in phishing.

Learn more

SPF complements DMARC. Both should be published. SPF records list authorized sending IPs (e.g., `v=spf1 include:_spf.google.com ~all` for Google Workspace). After publishing, verify in Google Postmaster Tools or mxtoolbox.

Source: RFC 7208 (SPF)

B
Crawlability
no robots.txt, no sitemap
REVIEW
no robots.txt, no sitemap
Info::
No robots.txt found
robots.txt is optional but recommended. It tells search engine crawlers which pages to index.
Info::
No sitemap.xml found
A sitemap helps search engines discover and index your pages more efficiently.

robots.txt is optional but recommended. It tells search engine crawlers which pages to index.

Why this matters

No robots.txt — crawlers fetch /robots.txt and get 404; not breaking but means default crawl behavior with no directives or sitemap reference.

Learn more

A minimal robots.txt with `User-agent: * / Allow: / / Sitemap: https://example.com/sitemap.xml` covers the basics. Without it, crawlers behave fine but lose the sitemap signal and can't be selectively blocked from crawl-traps.

Source: robotstxt.org

A sitemap helps search engines discover and index your pages more efficiently.

Why this matters

No sitemap.xml — Google relies on crawl-graph discovery alone, slowing indexing of deep or fresh URLs.

Learn more

A sitemap accelerates Google's discovery of new and updated content. Most CMSes auto-generate one; static-site frameworks need a build-step plugin. Reference it from robots.txt and submit in Search Console to confirm Google can fetch it.

Source: sitemaps.org / Google Search Central

robots.txt No robots.txt found

No robots.txt found

This is fine for most sites — a missing robots.txt allows all crawling by default.

sitemap.xml No sitemap found

No sitemap found

Adding a sitemap helps search engines discover your pages.

B
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
REVIEW
www/non-www, trailing slash, HTTP→HTTPS
Critical::
Both www and non-www versions serve content
Got: Both variants return 200 Expected: One variant 301-redirects to the other
Info::
HTTP correctly 301-redirects to HTTPS

www / non-www

200https://www.kernel.org/
200https://kernel.org/

Inconsistent — duplicate content risk

HTTP → HTTPS

301http://www.kernel.org/ https://www.kernel.org/

Consistent

B
TLS Certificate Expiry & Recommendations
193 days until leaf cert expires — 4 issues to address
REVIEW

Certificate validity

193
days left
0d 30d 60d 90d+

Recommended actions

  • Add includeSubDomains to the HSTS directive
  • Add the preload directive and submit to hstspreload.org once max-age + includeSubDomains are in place
  • Enable DNSSEC on your domain for DNS spoofing protection
  • Enable OCSP stapling on your TLS server to remove a CA roundtrip and protect user privacy
A+
Redirect Chain
No redirects — direct access
PASS
No redirects — direct access
Info::
No redirects — direct access
Got: https://www.kernel.org

https://www.kernel.org

5 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://www.kernel.org2005 msHTTP/1.1nginx
A+
IPv6 Readiness
IPv6 reachable (0 ms)
PASS
IPv6 reachable (0 ms)
Info::
IPv6 is configured and reachable at 2a04:4e42:600::311, 2a04:4e42:200::311, 2a04:4e42:400::311, 2a04:4e42::311
Got: 0 ms connect
IPv6 Ready
AAAA Records 2a04:4e42:600::311, 2a04:4e42:200::311, 2a04:4e42:400::311, 2a04:4e42::311 Connection Reachable (0 ms)
A+
Domain Intelligence
kernel.org — via Gandi SAS, 29 years, 6 months old
PASS
kernel.org — via Gandi SAS, 29 years, 6 months old
Info::
Domain registered until Mar 8, 2027 (11 months remaining)
Info::
DNSSEC is not enabled
DNSSEC protects against DNS spoofing attacks. While not required, enabling DNSSEC adds an additional layer of security. Contact your DNS provider to enable it.
Info::
Registrar: Gandi SAS
Domain expiry

239 days

March 8, 2027

SSL certificate

193 days

Issued by GlobalSign nv-sa

Domain age

29 years, 6 months

Registered March 7, 1997

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

Unknown

2600:3c04:e001:324:0:1991:8:25

Registrar

Gandi SAS

Lock status unknown 6 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Recommended actions
  • Enable DNSSEC to protect visitors from DNS spoofing
Registrar Gandi SAS
Created March 7, 1997 (29 years, 6 months ago)
Expires March 8, 2027 (11 months)
Last Updated May 28, 2025
Name Servers ns11.constellix.com, ns21.constellix.com, ns31.constellix.com, ns41.constellix.net, ns51.constellix.net, ns61.constellix.net
DNSSEC Not enabled
Hosting
IP Address 2600:3c04:e001:324:0:1991:8:25
Data source: rdap (0.2s)

DNSSEC protects against DNS spoofing attacks. While not required, enabling DNSSEC adds an additional layer of security. Contact your DNS provider to enable it.

Why this matters

Without DNSSEC, an attacker who can poison your DNS can hijack your domain — and SSL certs alone don't stop them.

Learn more

DNSSEC adds cryptographic signatures to DNS records, preventing forged responses from poisoning resolver caches. Without it, an attacker who controls the network path can redirect your domain to a malicious server before any HTTPS handshake happens. Most modern registrars (Cloudflare, Google Domains, Route 53) enable it with one toggle.

Source: ICANN / RFC 4033

A+
HTTP Probe Timing
Total 30 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
24 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
1 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
4 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
30 ms
Total Time Total request time from DNS lookup through full response.
30 ms

Connection waterfall

DNS Lookup 24 ms TCP Connect 1 ms TLS Handshake 4 ms Server Processing 2 ms Content Transfer 0 ms
A+
CDN & Delivery
Fastly (HIT)
PASS
Fastly (HIT)
Info::
Site is served via Fastly CDN
Got: x-served-by: cache-toj-leto2350070-TOJ
Info::
CDN cache status: HIT
CDN Detected: Fastly
Provider Fastly Cache Status HIT Evidence x-served-by: cache-toj-leto2350070-TOJ
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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