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https://computerhistory.org

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
88
GRADE
B
FIX
1
REVIEW
1
PASS
7
INFO
0
Probed from Santa Clara, United States
200 OK
Checks
9
7 PASS 1 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: 2606:4700:3035::ac43:b29a, 2606:4700:3035::6815:11dc
Info::
IPv6 connection error
Got: dial tcp6 [2606:4700:3035::ac43:b29a]:443: connect: network is unreachable
IPv6 Misconfigured
AAAA Records 2606:4700:3035::ac43:b29a, 2606:4700:3035::6815:11dc 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
TLS Certificate Expiry & Recommendations
75 days until leaf cert expires — 5 issues to address
REVIEW

Certificate validity

75
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
2 A records, 22 ms lookup
PASS
2 A records, 22 ms lookup
Info::
Resolves to 2 IPv4 address(es)
Got: 172.67.178.154, 104.21.17.220
Info::
Has 2 IPv6 (AAAA) record(s)
Got: 2606:4700:3035::ac43:b29a, 2606:4700:3035::6815:11dc
Info::
2 nameserver(s) configured
Got: mia.ns.cloudflare.com, randy.ns.cloudflare.com
Info::
1 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: 22 ms
Got: 22 ms
A172.67.178.154, 104.21.17.220
AAAA2606:4700:3035::ac43:b29a, 2606:4700:3035::6815:11dc
CNAME—
NSmia.ns.cloudflare.com, randy.ns.cloudflare.com
MX
0 computerhistory-org.mail.protection.outlook.com
TXT
1JPhzj9k7fEHgtsngDZNS6yfV03c0x5VyuvqC4odAJkWfpEFvI9mD72+vQiSbKOtDMvUyMNqklKmOw+O...
MS=498D467512A4DA933158597F4042806719B8E25B
MS=ms12064115
_globalsign-domain-verification=a0QaafMZgRS0DbVMw3XLx2rdUg41VfP9I_fBBuSk-m
_globalsign-domain-verification=w4J1QxPn3aNctgVGzY51pbeSFxpzwNCjLN4HV-i699
apple-domain-verification=zj49fL4xByFmwuNN
docusign=5c1c9cad-846f-41c0-9049-a0cbe3169cfb
facebook-domain-verification=og8r6zl8mxkeszsryklveiywpkyzuq
gJPngtlEoee5tmwh7SsQYLjyX5sIac7gbdszvgbHPluMG1oiUo8PIlF0NqxwNAHCjePqMKlQQgd2pg++...
google-site-verification=p5tnnWmagFi2txnFJKyqJhSWZaKddUMCc6sKK-zCX5M
lgpoa4pn3skmfbm0f4amo8fruc
mPvdaxG4vvybwa8VZI0J4AncjCIh3T75uHBGRwH3TSD1kU8XFwFx0yDDAbsgB7n+UZ3fAELT6dI16V6e...
nfM5CrwvDFasS6IfAOTkTvjNzm7gYjif2NEd49JW97+JBXBTD0dGmQDeyu/RnpXC76UvmzlMQm8KbMAN...
openai-domain-verification=dv-LxzDCWHjzW2cxVrmyRlJZ4So
rm_verify=b4106fa28e
SPF v=spf1 include:spf.protection.outlook.com include:_spf.psm.knowbe4.com include:s...
CAALookup not available with standard resolver
Resolved in 22 ms

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
No redirects — direct access
PASS
No redirects — direct access
Info::
No redirects — direct access
Got: https://computerhistory.org

https://computerhistory.org

44 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://computerhistory.org20044 msHTTP/1.1cloudflare
A+
Crawlability
robots.txt present, sitemap with 14 URLs
PASS
robots.txt present, sitemap with 14 URLs
Info::
robots.txt is present
Got: 177 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 14 entries
Info::
Sitemap index with 14 child sitemaps
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 177 B Sitemaps referenced 1 User-agents * Blocking No — crawling allowed
# START YOAST BLOCK
# ---------------------------
User-agent: *
Disallow:

Sitemap: https://computerhistory.org/sitemap_index.xml
# ---------------------------
# END YOAST BLOCK
sitemap.xml 200 OK
Type Sitemap Index URLs 14 entries Valid XML Yes
Child Sitemaps:
A+
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
PASS
www/non-www, trailing slash, HTTP→HTTPS
Info::
www/non-www redirect configured correctly (preferred: non-www)
Info::
HTTP correctly 301-redirects to HTTPS

www / non-www

302https://www.computerhistory.org/
200https://computerhistory.org/

Preferred variant: non-www

HTTP → HTTPS

301http://computerhistory.org/ → https://computerhistory.org/

Consistent

A+
Domain Intelligence
computerhistory.org — via Cloudflare, Inc., 28 years, 7 months old, hosted on Cloudflare
PASS
computerhistory.org — via Cloudflare, Inc., 28 years, 7 months old, hosted on Cloudflare
Info::
Domain registered until Feb 2, 2027 (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: Cloudflare, Inc.
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.
Info::
Hosting: Cloudflare
Got: AS13335
Domain expiry

231 days

February 2, 2027

SSL certificate

75 days

Issued by Google Trust Services

Domain age

28 years, 7 months

Registered February 3, 1998

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

Cloudflare

ASN AS13335

104.21.17.220

Registrar

Cloudflare, Inc.

Unlocked 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
  • Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
Registrar Cloudflare, Inc.
Created February 3, 1998 (28 years, 7 months ago)
Expires February 2, 2027 (9 months)
Last Updated March 30, 2025
Name Servers mia.ns.cloudflare.com, randy.ns.cloudflare.com
DNSSEC Not enabled
Hosting
IP Address 104.21.17.220
ASN AS13335 (CLOUDFLARENET - Cloudflare, Inc., US)
Provider Cloudflare
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

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

Connection waterfall

DNS Lookup 25 ms TCP Connect 4 ms TLS Handshake 10 ms Server Processing 25 ms Content Transfer 1 ms
A
CDN & Delivery
Cloudflare (DYNAMIC)
PASS
Cloudflare (DYNAMIC)
Info::
Site is served via Cloudflare CDN (edge: SJC)
Got: cf-ray: 9f07647709f597d9-SJC
Info::
CDN cache status: DYNAMIC
CDN Detected: Cloudflare
Provider Cloudflare Cache Status DYNAMIC Evidence cf-ray: 9f07647709f597d9-SJC
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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