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Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
74
GRADE
C
FIX
2
REVIEW
5
PASS
2
INFO
0
Probed from Singapore, Singapore
200 OK
Checks
9
2 PASS 5 REVIEW 2 FIX
F
IPv6 Readiness
Action
IPv6 records exist but unreachable
FIX
IPv6 records exist but unreachable
Warning::
IPv6 DNS records exist but server is not reachable
Having AAAA records but an unreachable server is worse than no AAAA — clients may experience delays before falling back to IPv4.
Got: 2610:28:3090:3000:0:bad:cafe:47
Info::
IPv6 connection error
Got: dial tcp6 [2610:28:3090:3000:0:bad:cafe:47]:443: i/o timeout
IPv6 Misconfigured
AAAA Records 2610:28:3090:3000:0:bad:cafe:47 Connection UNREACHABLE

Having AAAA records but an unreachable server is worse than no AAAA — clients may experience delays before falling back to IPv4.

Why this matters

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)

D
CDN & Delivery
Action
No CDN detected
FIX
No CDN detected
Warning::
No CDN detected
A CDN can significantly improve load times for users around the world by caching content at edge nodes closer to them.
No CDN detected

Consider using a CDN to improve global delivery speed and reduce origin load.

B
DNS Records
1 A records, 472 ms lookup
REVIEW
1 A records, 472 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 152.19.134.47
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
Info::
Has 1 IPv6 (AAAA) record(s)
Got: 2610:28:3090:3000:0:bad:cafe:47
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: gutenberg.org
Info::
2 nameserver(s) configured
Got: ns2.unc.edu, ns.unc.edu
Info::
7 mail exchanger(s) configured
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'.
Warning::
DNS resolution is slow (472 ms)
Slow DNS adds latency to every page load. Consider a faster DNS provider.
Got: 472 ms
A152.19.134.47
AAAA2610:28:3090:3000:0:bad:cafe:47
CNAMEgutenberg.org
NSns2.unc.edu, ns.unc.edu
MX
10 aspmx.l.google.com
20 alt1.aspmx.l.google.com
20 alt2.aspmx.l.google.com
30 aspmx3.googlemail.com
30 aspmx4.googlemail.com
30 aspmx2.googlemail.com
30 aspmx5.googlemail.com
TXT
google-site-verification=Pdx3wFBIiPEEeFgk1mMu_nljd4YYt6W7royvvBURaSU
CAALookup not available with standard resolver
Resolved in 472 ms

Multiple A records provide failover if one server goes down.

Why this matters

Single A record means a single point of failure — if that IP goes down, your site is unreachable until DNS TTL expires.

Learn more

Add multiple A records for round-robin failover, or use a managed DNS provider with health-checked failover (Route 53, Cloudflare, NS1). Short TTL (60-300s) lets clients recover faster on outages.

Source: SRE practice / DNS architecture

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)

Slow DNS adds latency to every page load. Consider a faster DNS provider.

Why this matters

DNS resolution is slow — anycast DNS providers (Cloudflare, Route 53) typically resolve <50ms globally.

Source: DNS performance benchmarks

B
Crawlability
robots.txt present, no sitemap
REVIEW
robots.txt present, no sitemap
Info::
robots.txt is present
Got: 40 bytes
Info::
No sitemap.xml found
A sitemap helps search engines discover and index your pages more efficiently.
Info::
robots.txt does not reference a sitemap
Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

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

Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

Why this matters

robots.txt omits Sitemap: directive — crawlers must fetch /sitemap.xml by convention; reliable but missing the explicit hint.

Source: sitemaps.org

robots.txt 200 OK
Size 40 B Sitemaps referenced 0 User-agents * Blocking No — crawling allowed
User-agent: *
Disallow: /ebooks/search


sitemap.xml No sitemap found

No sitemap found

Adding a sitemap helps search engines discover your pages.

C
URL Variants
Action
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
Warning::
HTTP→HTTPS redirect uses 302 instead of 301
Got: 302 temporary redirect Expected: 301 permanent redirect

www / non-www

200https://www.gutenberg.org/
200https://gutenberg.org/

Inconsistent — duplicate content risk

HTTP → HTTPS

302http://www.gutenberg.org/ https://www.gutenberg.org/

Use 301 (permanent) instead of 302 (temporary)

C
HTTP Probe Timing
Action
Total 1642 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
REVIEW
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
236 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
237 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
693 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
1.64 s
Total Time Total request time from DNS lookup through full response.
1.64 s

Connection waterfall

DNS Lookup 236 ms TCP Connect 237 ms TLS Handshake 693 ms Server Processing 473 ms Content Transfer 4 ms
B
TLS Certificate Expiry & Recommendations
221 days until leaf cert expires — 3 issues to address
REVIEW

Certificate validity

221
days left
0d 30d 60d 90d+

Recommended actions

  • Enable HSTS: Strict-Transport-Security: max-age=31536000; includeSubDomains
  • 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.gutenberg.org

https://www.gutenberg.org

1592 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://www.gutenberg.org2001592 msHTTP/1.1Apache
A+
Domain Intelligence
gutenberg.org — via Network Solutions, LLC, 29 years, 9 months old
PASS
gutenberg.org — via Network Solutions, LLC, 29 years, 9 months old
Info::
Domain registered until Nov 30, 2033 (7 years, 9 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: Network Solutions, LLC
Domain expiry

2697 days

November 30, 2033

SSL certificate

221 days

Issued by Network Solutions L.L.C.

Domain age

29 years, 9 months

Registered December 1, 1996

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

Unknown

2610:28:3090:3000:0:bad:cafe:47

Registrar

Network Solutions, LLC

Lock status unknown 2 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 Network Solutions, LLC
Created December 1, 1996 (29 years, 9 months ago)
Expires November 30, 2033 (7 years, 9 months)
Last Updated December 5, 2023
Name Servers ns.unc.edu, ns2.unc.edu
DNSSEC Not enabled
Hosting
IP Address 2610:28:3090:3000:0:bad:cafe:47
Data source: rdap (0.6s)

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

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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