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https://uva.nl

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
86
GRADE
B
FIX
1
REVIEW
3
PASS
5
INFO
0
Probed from Madrid, Spain
301 Moved Permanently
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

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.uva.nl/
200https://uva.nl/

Inconsistent — duplicate content risk

HTTP → HTTPS

301http://uva.nl/ → https://uva.nl:443/

Consistent

B
TLS Certificate Expiry & Recommendations
107 days until leaf cert expires — 3 issues to address
REVIEW

Certificate validity

107
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 OCSP stapling on your TLS server to remove a CA roundtrip and protect user privacy
A+
DNS Records
2 A records, 39 ms lookup
PASS
2 A records, 39 ms lookup
Info::
Resolves to 2 IPv4 address(es)
Got: 76.223.53.36, 52.223.0.124
Info::
No IPv6 (AAAA) records
Info::
4 nameserver(s) configured
Got: ns2.uha.nl, ns1.uha.nl, ns3.surfnet.nl, ns1.zurich.surf.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: 39 ms
Got: 39 ms
A76.223.53.36, 52.223.0.124
AAAA—
CNAME—
NSns2.uha.nl, ns1.uha.nl, ns3.surfnet.nl, ns1.zurich.surf.net
MX
10 uva-nl.t-v1.mx.microsoft
TXT
atlassian-domain-verification=fgCYupj4jgwsJq920dddvuWFDvBa7KVzk4tXTPKHJbIll1Qwso...
google-site-verification=gzDIq68FRHfFkpkqxOR7eopF9yxPHV3llfbezSftDTk
mandrill_verify.3B_nbZvNtDJKVeqvNhSmEA
amazonses:CyLXggQPAImSKm+6w68od2EhK8JNG4UseLcnwVy/6Rg=
HARICA-iRdvnXUvsCenHVtW35t
ZOOM_verify_5SDyNZLJSPWYTWoGkjFXog
google-site-verification=fx8Mt-sj-00QqB-cI_bRwu3odAnEdgU0ExBF-sg281U
MS=ms30720995
bjhgZnR4NeBHRjg5zqc39zKt+iyoiYs5dv6G3GipT9hqK/q0ZjPjfZhOV+GR2gbLBrtKYTcmwpc4fZjV...
brevo-code:827311f17475d789ad60ba0974d0be19
k5fwoEFArB0YP9tJBXHjfg+vHi0TBfdkL0F/lNNaMIE1HbNFmGeZAoLhjo0giV3oWbtun4LEmvhqh4g+...
SPF v=spf1 ip4:145.18.56.76/31 ip4:13.74.56.125 ip4:87.195.18.70 ip4:94.228.137.42 i...
google-site-verification=XNCiP7FIhnVSl1bdy_mnhyXTkKrwx4RZvoSE398N16Y
fJ9bgKZY7Dqugd6Tbm3M3JUMYK7j3kUQWKDPw14ZIkF0E3y/EFW3y8p1qOezGdxiQxHsxsOA7xlD94eN...
CAALookup not available with standard resolver
Resolved in 39 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
1 redirect(s), 398 ms total
PASS
1 redirect(s), 398 ms total
Info::
Single redirect
Got: https://uva.nl → https://www.uva.nl/ (301)
Info::
WWW normalization redirect

https://uva.nl

113 ms · HTTP/1.1

301

https://www.uva.nl/

285 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://uva.nl301113 msHTTP/1.1Apache
2https://www.uva.nl/200285 msHTTP/1.1Apache

See the visual redirect chain in the HTTP Probe tab →

A+
Crawlability
robots.txt present, sitemap with 3 URLs
PASS
robots.txt present, sitemap with 3 URLs
Info::
robots.txt is present
Got: 0 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 3 entries
Info::
Sitemap index with 3 child sitemaps
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 0 B Sitemaps referenced 0 User-agents Blocking No — crawling allowed
sitemap.xml 200 OK
Type Sitemap Index URLs 3 entries Valid XML Yes
Child Sitemaps:
A+
Domain Intelligence
uva.nl — via Universiteit van Amsterdam, 38 years old, hosted on AWS
PASS
uva.nl — via Universiteit van Amsterdam, 38 years old, hosted on AWS
Info::
DNSSEC is enabled
Info::
Registrar: Universiteit van Amsterdam
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: AWS
Got: AS16509
Domain expiry

Unknown

SSL certificate

107 days

Issued by Sectigo Limited

Domain age

38 years

Registered October 12, 1988

DNSSEC

Enabled

Protects against DNS spoofing

Hosting

AWS

ASN AS16509

52.223.0.124

Registrar

Universiteit van Amsterdam

Unlocked 4 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 Universiteit van Amsterdam
Created October 12, 1988 (38 years ago)
Last Updated December 20, 2024
Name Servers ns1.zurich.surf.net, ns3.surfnet.nl, ns2.uha.nl, ns1.uha.nl
DNSSEC Enabled
Registrant Universiteit van Amsterdam
Hosting
IP Address 52.223.0.124
ASN AS16509 (AMAZON-02 - Amazon.com, Inc., US)
Provider AWS
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 155 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
34 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.
77 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
155 ms
Total Time Total request time from DNS lookup through full response.
155 ms

Connection waterfall

DNS Lookup 34 ms TCP Connect 1 ms TLS Handshake 77 ms Server Processing 43 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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