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https://universiteitleiden.nl

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
85
GRADE
B
FIX
1
REVIEW
3
PASS
5
INFO
0
Probed from Madrid, Spain
302 Found
Checks
9
5 PASS 3 REVIEW 1 FIX
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.

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

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.universiteitleiden.nl/
200https://universiteitleiden.nl/

Inconsistent — duplicate content risk

HTTP → HTTPS

302http://universiteitleiden.nl/ → https://universiteitleiden.nl/

Use 301 (permanent) instead of 302 (temporary)

B
TLS Certificate Expiry & Recommendations
117 days until leaf cert expires — 2 issues to address
REVIEW

Certificate validity

117
days left
0d 30d 60d 90d+

Recommended actions

  • Enable HSTS: Strict-Transport-Security: max-age=31536000; includeSubDomains
  • Enable OCSP stapling on your TLS server to remove a CA roundtrip and protect user privacy
A+
DNS Records
1 A records, 50 ms lookup
PASS
1 A records, 50 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 132.229.29.70
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
Info::
No IPv6 (AAAA) records
Info::
3 nameserver(s) configured
Got: ns3.surfnet.nl, ns1.surfnet.nl, ns2.surfnet.nl
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: 50 ms
Got: 50 ms
A132.229.29.70
AAAA—
CNAME—
NSns3.surfnet.nl, ns1.surfnet.nl, ns2.surfnet.nl
MX
0 universiteitleiden-nl.k-v1.mx.microsoft
TXT
MHlhvquCdwRJRYkTS56GSEY+DQj+UiYMZF/IOe4KopQIx9o1tQw9R75rdXDd3wu3ipiXoQU024B59OvW...
MS=ms50955834
google-site-verification=lDW7ZJy_kHGpzCFC7kFYyj96huHupUonb0ytLJHIAdE
facebook-domain-verification=i7dmrn8v3p50vcpvbklhh2imk6ghos
HARICA-0McXXLaGRKvAAUnrbue
SPF v=spf1 include:_spf.xqueue.com ~all
CAALookup not available with standard resolver
Resolved in 50 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), 268 ms total
PASS
1 redirect(s), 268 ms total
Info::
Single redirect
Got: https://universiteitleiden.nl → https://www.universiteitleiden.nl/ (302)
Info::
WWW normalization redirect
Info::
Uses 302 (temporary) redirect
If permanent, use 301 instead.
Got: https://universiteitleiden.nl

https://universiteitleiden.nl

112 ms · HTTP/1.1

302

https://www.universiteitleiden.nl/

156 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://universiteitleiden.nl302112 msHTTP/1.1
2https://www.universiteitleiden.nl/200156 msHTTP/1.1

See the visual redirect chain in the HTTP Probe tab →

If permanent, use 301 instead.

Why this matters

302 (Found) is for genuinely temporary redirects — if this redirect is permanent, switch to 301 to preserve SEO equity.

Learn more ▾

Search engines treat 302 as temporary, keeping the original URL indexed and not transferring full link equity to the destination. Use 301 (Moved Permanently) for permanent redirects (HTTP→HTTPS, www-vs-non-www, URL restructures).

Source: Google Search Central

A+
Crawlability
robots.txt present, sitemap with 45 URLs
PASS
robots.txt present, sitemap with 45 URLs
Info::
robots.txt is present
Got: 145 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 45 entries
Info::
Sitemap index with 45 child sitemaps
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 145 B Sitemaps referenced 1 User-agents * Blocking No — crawling allowed


<pre>
User-agent: *
Disallow: /print
Disallow: /zoeken?*
Disallow: /en/search?*

Sitemap: https://www.universiteitleiden.nl/sitemap.xml
</pre>
sitemap.xml 200 OK
Type Sitemap Index URLs 45 entries Valid XML Yes
Child Sitemaps:
A+
Domain Intelligence
universiteitleiden.nl — via team.blue nl B.V., 25 years, 6 months old, hosted on SURFNET-NL SURFnet, The Netherlands, NL
PASS
universiteitleiden.nl — via team.blue nl B.V., 25 years, 6 months old, hosted on SURFNET-NL SURFnet, The Netherlands, NL
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.
Info::
Hosting: SURFNET-NL SURFnet, The Netherlands, NL
Got: AS1103
Domain expiry

Unknown

SSL certificate

117 days

Issued by Hellenic Academic and Research Institutions CA

Domain age

25 years, 6 months

Registered February 9, 2001

DNSSEC

Enabled

Protects against DNS spoofing

Hosting

SURFNET-NL SURFnet, The Netherlands, NL

ASN AS1103

132.229.29.70

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 February 9, 2001 (25 years, 6 months ago)
Last Updated December 19, 2024
Name Servers ns1.surfnet.nl, ns3.surfnet.nl, ns2.surfnet.nl
DNSSEC Enabled
Registrant Universiteit Leiden
Hosting
IP Address 132.229.29.70
ASN AS1103 (SURFNET-NL SURFnet, The Netherlands, NL)
Provider SURFNET-NL SURFnet, The Netherlands, NL
Data source: rdap (0.4s)

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

Connection waterfall

DNS Lookup 52 ms TCP Connect 31 ms TLS Handshake 40 ms Server Processing 42 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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