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Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
80
GRADE
B
FIX
1
REVIEW
2
PASS
6
INFO
0
Probed from Singapore, Singapore
301 Moved Permanently
Checks
9
6 PASS 2 REVIEW 1 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: 2620:12a:8000::3, 2620:12a:8001::3
Info::
IPv6 connection error
Got: dial tcp6 [2620:12a:8000::3]:443: connect: no route to host
IPv6 Misconfigured
AAAA Records 2620:12a:8000::3, 2620:12a:8001::3 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)

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.linux.com/
200https://linux.com/

Inconsistent — duplicate content risk

HTTP → HTTPS

301http://linux.com/ → https://linux.com/

Consistent

B
TLS Certificate Expiry & Recommendations
35 days until leaf cert expires — 5 issues to address
REVIEW

Certificate validity

35
days left
0d 30d 60d 90d+

Recommended actions

  • Extend HSTS max-age to at least 31536000 (1 year) to meet the preload list criteria
  • 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+
DNS Records
1 A records, 157 ms lookup
PASS
1 A records, 157 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 23.185.0.3
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
Info::
Has 2 IPv6 (AAAA) record(s)
Got: 2620:12a:8000::3, 2620:12a:8001::3
Info::
4 nameserver(s) configured
Got: ns1.dnsimple.com, ns2.dnsimple-edge.net, ns3.dnsimple.com, ns4.dnsimple-edge.org
Info::
2 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::
SPF record present in TXT
Info::
DNS resolution time: 157 ms
Got: 157 ms
A23.185.0.3
AAAA2620:12a:8000::3, 2620:12a:8001::3
CNAME—
NSns1.dnsimple.com, ns2.dnsimple-edge.net, ns3.dnsimple.com, ns4.dnsimple-edge.org
MX
10 mx1.forwardemail.net
10 mx2.forwardemail.net
TXT
8112310.spf10.hubspotemail.net
SPF v=spf1 ip4:198.145.29.98 include:_spf.google.com include:amazonses.com include:m...
globalsign-domain-verification=GAw3QxpoQCUd6MEBcIrvwmn1548c2kZ_M8jDU57Ho3
google-site-verification=AqV3SU_MRUY0GYnNYAKi_6pa0S1WU7hfq5SapcMUycI
google-site-verification=SDW6U9788xC80xinO4aDxrgD4bkaCjLozXPv4R7oMbk
google-site-verification=oGlHyAcoij5H-f9oD_WyPZLySBNASgAGQxkmbrKFblo
forward-email-site-verification=JV5pfF4sKV
CAALookup not available with standard resolver
Resolved in 157 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

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.

A
Redirect Chain
1 redirect(s), 192 ms total
PASS
1 redirect(s), 192 ms total
Info::
Single redirect
Got: https://linux.com → https://www.linux.com/ (301)
Info::
WWW normalization redirect

https://linux.com

175 ms · HTTP/1.1

301

https://www.linux.com/

17 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://linux.com301175 msHTTP/1.1nginx
2https://www.linux.com/20017 msHTTP/1.1nginx

See the visual redirect chain in the HTTP Probe tab →

A+
Crawlability
robots.txt present, sitemap with 115 URLs
PASS
robots.txt present, sitemap with 115 URLs
Info::
robots.txt is present
Got: 114 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 115 entries
Info::
Sitemap index with 115 child sitemaps
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 114 B Sitemaps referenced 1 User-agents * Blocking No — crawling allowed
User-agent: *
Disallow: /wp-admin/
Allow: /wp-admin/admin-ajax.php

Sitemap: https://www.linux.com/wp-sitemap.xml
sitemap.xml 200 OK
Type Sitemap Index URLs 115 entries Valid XML Yes
Child Sitemaps:
A
Domain Intelligence
linux.com — via 1API GmbH, 32 years, 4 months old
PASS
linux.com — via 1API GmbH, 32 years, 4 months old
Warning::
Domain expires in 36 days
Consider enabling auto-renewal to prevent accidental expiration.
Got: Expires Jun 1, 2026
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: 1API GmbH
Warning::
Registrar lock is NOT enabled
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.
Domain expiry

EXPIRED

June 1, 2026

SSL certificate

35 days

Issued by Let's Encrypt

Domain age

32 years, 4 months

Registered June 2, 1994

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

Unknown

2620:12a:8000::3

Registrar

1API GmbH

Unlocked 4 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Recommended actions
  • Domain has EXPIRED — renew immediately to avoid total site outage
  • Enable DNSSEC to protect visitors from DNS spoofing
  • Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
Registrar 1API GmbH
Created June 2, 1994 (32 years, 4 months ago)
Expires June 1, 2026 (1 months)
Last Updated November 23, 2025
Name Servers ns1.dnsimple.com, ns2.dnsimple-edge.net, ns3.dnsimple.com, ns4.dnsimple-edge.org
DNSSEC Not enabled
Hosting
IP Address 2620:12a:8000::3
Data source: rdap (0.1s)

Consider enabling auto-renewal to prevent accidental expiration.

Why this matters

Domain expiry approaching — renew immediately and ensure auto-renew + alerting are configured.

Source: ICANN renewal policy

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

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.

Why this matters

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

A+
HTTP Probe Timing
Total 89 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
74 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.
89 ms
Total Time Total request time from DNS lookup through full response.
89 ms

Connection waterfall

DNS Lookup 74 ms TCP Connect 1 ms TLS Handshake 4 ms Server Processing 11 ms Content Transfer 0 ms
A+
CDN & Delivery
Fastly (HIT, HIT, MISS, MISS)
PASS
Fastly (HIT, HIT, MISS, MISS)
Info::
Site is served via Fastly CDN
Got: x-served-by: cache-chi-klot8100057-CHI, cache-sin-wsat1880038-SIN, cache-sin-wsat1880036-SIN, cache-sin-wsat1880036-SIN
Info::
CDN cache status: HIT, HIT, MISS, MISS
CDN Detected: Fastly
Provider Fastly Cache Status HIT, HIT, MISS, MISS Evidence x-served-by: cache-chi-klot8100057-CHI, cache-sin-wsat1880038-SIN, cache-sin-wsat1880036-SIN, cache-sin-wsat1880036-SIN
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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