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https://classlink.com

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
86
GRADE
B
FIX
0
REVIEW
4
PASS
5
INFO
0
Probed from Madrid, Spain
301 Moved Permanently
Checks
9
5 PASS 4 REVIEW
C
IPv6 Readiness
Action
No IPv6 support
REVIEW
No IPv6 support
Info::
No IPv6 (AAAA) records found
IPv6 support is increasingly important for global accessibility. About 40% of internet users have IPv6 connectivity.
No IPv6 Support
About 40% of internet users have IPv6. Consider adding AAAA records.

IPv6 support is increasingly important for global accessibility. About 40% of internet users have IPv6 connectivity.

Why this matters

No AAAA records — same impact as 'no IPv6 (AAAA) records'; IPv6-preferring clients pay extra latency falling back to IPv4.

Source: Google IPv6 stats

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.classlink.com/
200https://classlink.com/

Inconsistent — duplicate content risk

HTTP → HTTPS

301http://classlink.com/ https://classlink.com/

Consistent

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

Certificate validity

83
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
B
CDN & Delivery
Cloudflare (BYPASS)
REVIEW
Cloudflare (BYPASS)
Info::
Site is served via Cloudflare CDN (edge: MAD)
Got: cf-ray: 9efe868e7f1518b2-MAD
Info::
CDN cache status: BYPASS
CDN Detected: Cloudflare
Provider Cloudflare Cache Status BYPASS Evidence cf-ray: 9efe868e7f1518b2-MAD
A+
DNS Records
1 A records, 46 ms lookup
PASS
1 A records, 46 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 198.202.211.1
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
Info::
No IPv6 (AAAA) records
Info::
4 nameserver(s) configured
Got: ns-261.awsdns-32.com, ns-1522.awsdns-62.org, ns-2026.awsdns-61.co.uk, ns-828.awsdns-39.net
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: 46 ms
Got: 46 ms
A198.202.211.1
AAAA
CNAME
NSns-261.awsdns-32.com, ns-1522.awsdns-62.org, ns-2026.awsdns-61.co.uk, ns-828.awsdns-39.net
MX
0 classlink-com.mail.protection.outlook.com
TXT
apple-domain-verification=YkDFx5z01YEISXVD
anthropic-domain-verification-xjj7xz=iR7ykRURIR8m1TufjvHBSTscf
Foxit-domain-verification=61cb92e4e7446ae2c9505ca5a853b955
linear-domain-verification=c5ruhesasc9j
logmein-verification-code=ce6036fe-d2c1-4676-980a-953230408dae
p344lhnhr36vrk6csonrdjkmc1
google-site-verification=6rOpTcmbg9b4Cft2EHJWjRuWQJulhd0NmWpjFTaNBUw
atlassian-domain-verification=Umlva1cUR4QjS03+6saVBhzTV4/ulItYeC+NDmsly/D9JzcbaE...
google-site-verification=zwbqDXH-crJlGAYdIYG5fl9FdRzglZHal9MYPeR_klM
qbovvtand4i23tcrc8nuptig5g
9vu5elj96pu6pob1ecp4j5c5dd
SPF v=spf1 include:aspmx.pardot.com include:stspg-customer.com include:sendgrid.net ...
status-page-domain-verification=rczds3yf1nz9
4qr0lkf6uog34p5a1046dm0tvu
5je1dbqftgftqf2sapptb20988
openai-domain-verification=dv-ed2walzHKaS2my4YbufodW2X
CAALookup not available with standard resolver
Resolved in 46 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), 370 ms total
PASS
1 redirect(s), 370 ms total
Info::
Single redirect
Got: https://classlink.com → https://www.classlink.com/ (301)
Info::
WWW normalization redirect

https://classlink.com

269 ms · HTTP/1.1

301

https://www.classlink.com/

101 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://classlink.com301269 msHTTP/1.1cloudflare
2https://www.classlink.com/200101 msHTTP/1.1cloudflare

See the visual redirect chain in the HTTP Probe tab →

A+
Crawlability
robots.txt present, sitemap with 1280 URLs
PASS
robots.txt present, sitemap with 1280 URLs
Info::
robots.txt is present
Got: 46 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 1280 entries
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 46 B Sitemaps referenced 1 User-agents Blocking No — crawling allowed
Sitemap: https://www.classlink.com/sitemap.xml
A+
Domain Intelligence
classlink.com — via Amazon Registrar, Inc., 28 years, 7 months old, hosted on Cloudflare
PASS
classlink.com — via Amazon Registrar, Inc., 28 years, 7 months old, hosted on Cloudflare
Info::
Domain registered until Jan 29, 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: Amazon Registrar, 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: AS209242
Domain expiry

229 days

January 29, 2027

SSL certificate

83 days

Issued by Google Trust Services

Domain age

28 years, 7 months

Registered January 30, 1998

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

Cloudflare

ASN AS209242

198.202.211.1

Registrar

Amazon Registrar, Inc.

Unlocked 4 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 Amazon Registrar, Inc.
Created January 30, 1998 (28 years, 7 months ago)
Expires January 29, 2027 (9 months)
Last Updated December 25, 2025
Name Servers ns-1522.awsdns-62.org, ns-2026.awsdns-61.co.uk, ns-261.awsdns-32.com, ns-828.awsdns-39.net
DNSSEC Not enabled
Hosting
IP Address 198.202.211.1
ASN AS209242 (CLOUDFLARESPECTRUM 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 272 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
45 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.
7 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
272 ms
Total Time Total request time from DNS lookup through full response.
272 ms

Connection waterfall

DNS Lookup 45 ms TCP Connect 1 ms TLS Handshake 7 ms Server Processing 220 ms Content Transfer 0 ms
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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