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https://www.harlingen.nl

Infrastructure

· 17 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
90
GRADE
A
FIX
0
REVIEW
8
PASS
9
INFO
0
Probed from Madrid, Spain
200 OK
Checks
17
9 PASS 8 REVIEW
B
DNS Records
3 A records, 68 ms lookup
REVIEW
3 A records, 68 ms lookup
Info::
Resolves to 3 IPv4 address(es)
Got: 91.241.6.164, 91.241.6.185, 91.241.6.46
Info::
Has 3 IPv6 (AAAA) record(s)
Got: 2001:678:264:4611::12, 2001:678:264:4612::12, 2001:678:264:4610::12
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: harlingen001.simgroephosting.nl
Info::
No NS records found
Info::
No MX records — email not configured via DNS
Info::
No SPF record found in TXT records
SPF helps prevent email spoofing. Add a TXT record starting with 'v=spf1'.
Info::
DNS resolution time: 68 ms
Got: 68 ms
A91.241.6.164, 91.241.6.185, 91.241.6.46
AAAA2001:678:264:4611::12, 2001:678:264:4612::12, 2001:678:264:4610::12
CNAMEharlingen001.simgroephosting.nl
NS—
MX—
TXT—
CAALookup not available with standard resolver
Resolved in 68 ms

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

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)

B
DNSSEC
Unsigned (DNSSEC not deployed)
REVIEW
Unsigned (DNSSEC not deployed)
Info::
DNSSEC is not deployed
The zone is not DNSSEC-signed. Users on validating resolvers (Cloudflare 1.1.1.1, Quad9 9.9.9.9, growing default in mobile resolvers) get no protection against DNS spoofing for this domain. Most registrars now offer DNSSEC at a single click; consider enabling it for sites where authenticity matters (banking, healthcare, government).
C
Reverse DNS
Action
0/6 IPs match cert SAN
REVIEW
0/6 IPs match cert SAN
Info::
PTR lookup failed for 91.241.6.164: lookup 91.241.6.164: no such host
No reverse DNS record set for this IP. Common on bare cloud-VM IPs without provider-side PTR; not a security issue.
Info::
PTR lookup failed for 91.241.6.185: lookup 91.241.6.185: no such host
No reverse DNS record set for this IP. Common on bare cloud-VM IPs without provider-side PTR; not a security issue.
Info::
PTR lookup failed for 91.241.6.46: lookup 91.241.6.46: no such host
No reverse DNS record set for this IP. Common on bare cloud-VM IPs without provider-side PTR; not a security issue.
Info::
PTR lookup failed for 2001:678:264:4611::12: lookup 2001:678:264:4611::12: no such host
No reverse DNS record set for this IP. Common on bare cloud-VM IPs without provider-side PTR; not a security issue.
Info::
PTR lookup failed for 2001:678:264:4612::12: lookup 2001:678:264:4612::12: no such host
No reverse DNS record set for this IP. Common on bare cloud-VM IPs without provider-side PTR; not a security issue.
Info::
PTR lookup failed for 2001:678:264:4610::12: lookup 2001:678:264:4610::12: no such host
No reverse DNS record set for this IP. Common on bare cloud-VM IPs without provider-side PTR; not a security issue.
B
TLS Certificate Expiry & Recommendations
104 days until leaf cert expires — 2 issues to address
REVIEW

Certificate validity

104
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
C
CDN & Delivery
Action
Assets on AWS CloudFront (host cuatro.sim-cdn.nl, 66 assets); document served directly from origin
REVIEW
Assets on AWS CloudFront (host cuatro.sim-cdn.nl, 66 assets); document served directly from origin
Warning::
Document not behind existing CDN (AWS CloudFront serves the assets)
The page's subresources are delivered by AWS CloudFront (cuatro.sim-cdn.nl, 66 assets), but the HTML document itself comes straight from the origin. Routing the document through the CDN already in use is the cheapest latency win available here -- the provider relationship, the certificate and the config already exist. A short edge TTL with stale-while-revalidate suits HTML that changes often; if the response is genuinely per-user, edge TLS termination alone still removes a full round trip from every visitor's first byte.
Got: x-amz-cf-id: _VQpgYtdnf-LtZmi3SVhTbFmSTXUzxsV0Hk_0kKlUp6v4BCwqXIrOg==
Info::
Assets on AWS CloudFront: cuatro.sim-cdn.nl (assets: 66), cache Hit from cloudfront
Got: x-amz-cf-id: _VQpgYtdnf-LtZmi3SVhTbFmSTXUzxsV0Hk_0kKlUp6v4BCwqXIrOg==
Info::
Assets on AWS CloudFront: app.tolkie.nl (assets: 3), cache Hit from cloudfront
Got: x-amz-cf-id: rvIouI2pY161u8TKMLRMqoFMjLCri7gHQiwaNUzzQ5Mm9FhKenKuFA==
Info::
Assets on AWS CloudFront: harlingen.logging.simanalytics.nl (assets: 3), cache Miss from cloudfront
Got: x-amz-cf-id: qCX_dSFXcl7NZgr8PU0orNzP11OPj5awofAuyaZJ03fbxfcAWXQL2g==
Warning: Assets on a CDN, document is not: AWS CloudFront
Document origin not attributed

Asset hosts on a CDN

  • cuatro.sim-cdn.nl — AWS CloudFront · assets: 66 · Cache Status: Hit from cloudfront
  • app.tolkie.nl — AWS CloudFront · assets: 3 · Cache Status: Hit from cloudfront
  • harlingen.logging.simanalytics.nl — AWS CloudFront · assets: 3 · Cache Status: Miss from cloudfront

Other asset hosts

  • fonts.bunny.net — assets: 2 · below probe threshold
  • meldingen.fryslanveilig.nl — assets: 1 · below probe threshold

The heavy static files already ride an edge network, but every visitor still waits on the origin for the HTML itself. Routing the document through the same CDN is usually a config change rather than a migration: a short edge TTL with stale-while-revalidate for cacheable HTML, or edge TLS termination alone when the response is per-user.

B
CDN Cache Observability
No CDN cache-status headers in the response
REVIEW
No CDN cache-status headers in the response
Info::
No CDN cache-status headers in the response
Without an X-Cache / CF-Cache-Status / X-Vercel-Cache / Age header, you can't tell from outside whether a request hit the cache or went to origin. Operationally important: enables debugging stale-content reports and verifying cache rules. Most managed CDN platforms emit at least one of these by default; absence often means the platform's diagnostic headers are stripped at an upstream proxy.
B
Operational Status Page
No status page link detected
REVIEW
No status page link detected
Info::
No operational status page link detected
Status pages communicate planned maintenance and incidents to users -- a hallmark of operationally-mature services. Most SaaS teams publish one via Atlassian Statuspage, Instatus, BetterUptime, or a self-hosted Cachet. Smaller sites legitimately don't need one; flagged as Info, not a failure.
B
Health Check Endpoint
No conventional health endpoint found
REVIEW
No conventional health endpoint found
Info::
No conventional health endpoint found
Health endpoints (/health, /healthz, /status, /ping, /api/health) let uptime monitors, load balancers, and orchestration systems (Kubernetes, ECS, Fly.io) verify the service is alive. Marketing sites and small services often skip them legitimately; flagged as Info, not a failure. Probe results: /api/health: 404, /health: 404, /healthz: 404, /ping: 404, /status: connection error.
A+
Subdomain Takeover
No subdomain takeover risk detected
PASS
No subdomain takeover risk detected
Info::
CNAME does not point at a known takeover-able service
A
CAA Records
issue: digicert.com
PASS
issue: digicert.com
Info::
CAA issue tag present — authorized CA(s): digicert.com
Info::
No CAA iodef tag — won't be notified of failed issuance attempts
Add `0 iodef "mailto:security@example.com"` to receive notifications when a CA refuses issuance because it doesn't match your CAA policy. Useful signal for detecting issuance attempts by unauthorized CAs.
A
Multi-Resolver DNS Speed
Mean 51ms across 3 resolvers (spread 47ms)
PASS
Mean 51ms across 3 resolvers (spread 47ms)
Info::
Cloudflare: 24ms
Got: 24ms via 1.1.1.1:53
Info::
Google: 59ms
Got: 59ms via 8.8.8.8:53
Info::
Quad9: 71ms
Got: 71ms via 9.9.9.9:53
A+
Redirect Chain
No redirects — direct access
PASS
No redirects — direct access
Info::
No redirects — direct access
Got: https://www.harlingen.nl

https://www.harlingen.nl

188 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://www.harlingen.nl200188 msHTTP/1.1
A+
IPv6 Readiness
IPv6 reachable (34 ms)
PASS
IPv6 reachable (34 ms)
Info::
IPv6 is configured and reachable at 2001:678:264:4611::12, 2001:678:264:4612::12, 2001:678:264:4610::12
Got: 34 ms connect
IPv6 Ready
AAAA Records 2001:678:264:4611::12, 2001:678:264:4612::12, 2001:678:264:4610::12 Connection Reachable (34 ms)
A+
Crawlability
robots.txt present, sitemap with 962 URLs
PASS
robots.txt present, sitemap with 962 URLs
Info::
robots.txt is present
Got: 212 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 962 entries
Info::
robots.txt does not reference a sitemap
Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

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 212 B Sitemaps referenced 0 User-agents AhrefsBot, MJ12bot, PetalBot, Owlin, trendictionbot, dotbot, SemrushBot, scooperbot, SemrushBot-SA Blocking No — crawling allowed
User-agent: SemrushBot
User-agent: SemrushBot-SA
User-agent: AhrefsBot
User-agent: MJ12bot
User-agent: PetalBot
User-agent: Owlin
User-agent: trendictionbot
User-agent: dotbot
User-agent: scooperbot
Disallow: /
sitemap.xml 200 OK
Type URL Set URLs 962 entries Valid XML Yes
Sample URLs:
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: www)
Info::
HTTP correctly redirects to HTTPS permanently
Got: HTTP 301

www / non-www

200https://www.harlingen.nl/
301https://harlingen.nl/

Preferred variant: www

HTTP → HTTPS

301http://www.harlingen.nl/ → https://www.harlingen.nl/

Consistent

A+
Domain Intelligence
harlingen.nl — via team.blue nl B.V., 29 years, 2 months old
PASS
harlingen.nl — via team.blue nl B.V., 29 years, 2 months old
Info::
DNSSEC is enabled
Info::
Registrar: team.blue nl B.V.
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

Unknown

SSL certificate

104 days

Issued by DigiCert Inc

Domain age

29 years, 2 months

Registered January 28, 1998

DNSSEC

Enabled

Protects against DNS spoofing

Hosting

Unknown

2a05:d018:995:4607:12:4151:981a:a983

Registrar

team.blue nl B.V.

Unlocked 3 NS records
Expiry timeline
Today
+1 year
SSL expiry Danger zone (≤30 days)
Recommended actions
  • Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
Registrar team.blue nl B.V.
Created January 28, 1998 (29 years, 2 months ago)
Last Updated June 20, 2025
Name Servers ns01.frlinfra.nl, ns02.frlinfra.nl, ns04.frlinfra.nl
DNSSEC Enabled
Registrant REDACTED FOR PRIVACY
Hosting
IP Address 2a05:d018:995:4607:12:4151:981a:a983
Data source: rdap (0.3s)

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

Connection waterfall

DNS Lookup 104 ms TCP Connect 34 ms TLS Handshake 44 ms Server Processing 92 ms Content Transfer 47 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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