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https://tudelft.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.tudelft.nl/
200https://tudelft.nl/

Inconsistent — duplicate content risk

HTTP → HTTPS

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

Consistent

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

Certificate validity

184
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, 81 ms lookup
PASS
1 A records, 81 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 130.161.128.82
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
Info::
No IPv6 (AAAA) records
Info::
5 nameserver(s) configured
Got: ns1.surfnet.nl, ns2.tudelft.nl, ns2.surfnet.nl, ns1.tudelft.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: 81 ms
Got: 81 ms
A130.161.128.82
AAAA—
CNAME—
NSns1.surfnet.nl, ns2.tudelft.nl, ns2.surfnet.nl, ns1.tudelft.nl, ns1.zurich.surf.net
MX
10 tudelft-nl.mail.protection.outlook.com
TXT
HARICA-svOKy8ChPYfvbMCCCgv
jamf-site-verification=Ddcd23-bTSJECc10j2URmw
sendinblue-code:ef5755c78c2226424706a65a2413f0a1
openatts a=dns-did; p=did:ethr:0x49264cd8041010adf43a926436e0ac38c053c066#contro...
L4Rcgp2aufV3yNQT7HZ7nmdmW+S8VVsOkBuh2Rk4Z7WKyHrLcd/aKCgVE+sihdcNsi/LkDeS8otItlX8...
miro-verification=19371c38bfc06be58d667cbb59a02508a880607d
EYCG94TF05LGAIXGKNS3B4SXZ796W7SPSHUPP1E3M
google-site-verification=vlPyHrqp8W5EwG3sBPAoZXrMFzyYmVJeDlDshyLCrzk
SPF v=spf1 ip4:130.161.131.0/24 ip4:131.180.77.44 ip4:131.180.74.128/27 include:spf....
google-site-verification=_nk7k44TtWKQJSgLYer_J68BmKIY83V9Heax6u7oRRA
miro-verification=034228b8046d801ff6579bb93100816ce0fac54f
google-site-verification=xwRqT1z_-EE597mEH4Qfh_TQTFYhTS-bWoYM009P-E8
figma-domain-verification=608b37abc404e00a10b2771e20c76b415cd1832b5faf4e3c500a54...
amazonses:iyPCyEjMv6YpdMhVuagmzM+6PIiSZt+kj9J0DnmImnQ=
HARICA-aXJ2Kuvqc5hU8cVsyIR
adobe-idp-site-verification=6c308adba5fba6d4295d8d092b40f332747dd3b7896740e9ee3a...
apple-domain-verification=TWilLuVqEqmPHPlP
MS=ms66592311
successfactors-site-verification=NGMxMTBlMzQ5ZmFiZWRiMTU1ZWVkZDk4MTczYzE5ZDhhZTV...
HARICA-9s6oKKJ124kmU6v3f6A
CAALookup not available with standard resolver
Resolved in 81 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), 309 ms total
PASS
1 redirect(s), 309 ms total
Info::
Single redirect
Got: https://tudelft.nl → https://www.tudelft.nl/ (301)
Info::
WWW normalization redirect

https://tudelft.nl

102 ms · HTTP/1.1

301

https://www.tudelft.nl/

208 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://tudelft.nl301102 msHTTP/1.1
2https://www.tudelft.nl/200208 msHTTP/1.1

See the visual redirect chain in the HTTP Probe tab →

A+
Crawlability
robots.txt present, sitemap with 216 URLs
PASS
robots.txt present, sitemap with 216 URLs
Info::
robots.txt is present
Got: 163 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 216 entries
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 163 B Sitemaps referenced 1 User-agents * Blocking No — crawling allowed
User-agent: *
Allow: /
Disallow: /typo3/
Disallow: /typo3_src/
Disallow: /t3lib/
Disallow: /*?id=
Disallow: /*?*lookup
Sitemap: https://www.tudelft.nl/sitemap.xml
sitemap.xml 200 OK
Type URL Set URLs 216 entries Valid XML Yes
Sample URLs:
A+
Domain Intelligence
tudelft.nl — via Technische Universiteit Delft, 39 years, 3 months old, hosted on TUDELFT-NL DTO TUDELFT, The Netherlands - AS, NL
PASS
tudelft.nl — via Technische Universiteit Delft, 39 years, 3 months old, hosted on TUDELFT-NL DTO TUDELFT, The Netherlands - AS, NL
Info::
DNSSEC is enabled
Info::
Registrar: Technische Universiteit Delft
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: TUDELFT-NL DTO TUDELFT, The Netherlands - AS, NL
Got: AS1128
Domain expiry

Unknown

SSL certificate

184 days

Issued by Hellenic Academic and Research Institutions CA

Domain age

39 years, 3 months

Registered July 23, 1987

DNSSEC

Enabled

Protects against DNS spoofing

Hosting

TUDELFT-NL DTO TUDELFT, The Netherlands - AS, NL

ASN AS1128

130.161.128.82

Registrar

Technische Universiteit Delft

Unlocked 5 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 Technische Universiteit Delft
Created July 23, 1987 (39 years, 3 months ago)
Last Updated October 9, 2025
Name Servers ns1.surfnet.nl, ns2.surfnet.nl, ns1.tudelft.nl, ns2.tudelft.nl, ns1.zurich.surf.net
DNSSEC Enabled
Registrant Technische Universiteit Delft
Hosting
IP Address 130.161.128.82
ASN AS1128 (TUDELFT-NL DTO TUDELFT, The Netherlands - AS, NL)
Provider TUDELFT-NL DTO TUDELFT, The Netherlands - AS, NL
Data source: rdap (0.5s)

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 135 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
35 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.
38 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
136 ms
Total Time Total request time from DNS lookup through full response.
136 ms

Connection waterfall

DNS Lookup 35 ms TCP Connect 31 ms TLS Handshake 38 ms Server Processing 31 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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