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.
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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)
DHTTP Probe TimingActionTotal 2340 ms — DNS, TCP, TLS, TTFB, content transfer breakdownFIX
Connection waterfall
BDNS Records2 A records, 2328 ms lookupREVIEW
| A | 52.52.192.191, 13.52.188.95 |
| AAAA | 2600:1f1c:446:4900::258, 2600:1f1c:446:4900::259 |
| CNAME | erlang-org.netlify.app |
| NS | — |
| MX | — |
| TXT | — |
| CAA | Lookup not available with standard resolver |
A CNAME at the zone apex can break MX and NS records. Use ALIAS/ANAME or A records instead.
CNAME at the apex (example.com) breaks every other apex record (MX, TXT, NS) — DNS-protocol violation per RFC 1034.
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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.
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'.
Without SPF, receiving servers can't validate sending IPs — your domain is easier to spoof in phishing.
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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)
Slow DNS adds latency to every page load. Consider a faster DNS provider.
DNS resolution is slow — anycast DNS providers (Cloudflare, Route 53) typically resolve <50ms globally.
Source: DNS performance benchmarks
BCrawlabilityno robots.txt, no sitemapREVIEW
robots.txt is optional but recommended. It tells search engine crawlers which pages to index.
No robots.txt — crawlers fetch /robots.txt and get 404; not breaking but means default crawl behavior with no directives or sitemap reference.
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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.
No sitemap.xml — Google relies on crawl-graph discovery alone, slowing indexing of deep or fresh URLs.
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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
No robots.txt found
This is fine for most sites — a missing robots.txt allows all crawling by default.
No sitemap found
Adding a sitemap helps search engines discover your pages.
BTLS Certificate Expiry & Recommendations33 days until leaf cert expires — 4 issues to addressREVIEW
Certificate validity
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
BCDN & DeliveryNetlifyREVIEW
A+Redirect ChainNo redirects — direct accessPASS
https://www.erlang.org
2343 ms · HTTP/1.1 FINAL
| # | URL | Status | Time | Protocol | Server |
|---|---|---|---|---|---|
| 1 | https://www.erlang.org | 200 | 2343 ms | HTTP/1.1 | Netlify |
A+URL Variantswww/non-www, trailing slash, HTTP→HTTPSPASS
www / non-www
Preferred variant: www
HTTP → HTTPS
Consistent
A+Domain Intelligenceerlang.org — via CSC Corporate Domains, Inc., 27 years, 10 months old, hosted on ERI-AS - Ericsson Inc., USPASS
87 days
October 8, 2026
33 days
Issued by Let's Encrypt
27 years, 10 months
Registered October 9, 1998
Not enabled
Protects against DNS spoofing
ERI-AS - Ericsson Inc., US
ASN AS158
192.121.151.106
CSC Corporate Domains, Inc.
Expiry timeline
Recommended actions
- Renew the domain or enable auto-renewal to prevent accidental expiry
- Enable DNSSEC to protect visitors from DNS spoofing
DNSSEC protects against DNS spoofing attacks. While not required, enabling DNSSEC adds an additional layer of security. Contact your DNS provider to enable it.
Without DNSSEC, an attacker who can poison your DNS can hijack your domain — and SSL certs alone don't stop them.
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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