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https://rug.nl

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
91
GRADE
A
FIX
1
REVIEW
2
PASS
6
INFO
0
Probed from Madrid, Spain
301 Moved Permanently
Checks
9
6 PASS 2 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
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.rug.nl/
200https://rug.nl/

Inconsistent — duplicate content risk

HTTP → HTTPS

302http://rug.nl/ https://rug.nl/

Use 301 (permanent) instead of 302 (temporary)

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

Certificate validity

223
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
A+
DNS Records
1 A records, 31 ms lookup
PASS
1 A records, 31 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 129.125.2.51
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
Info::
Has 1 IPv6 (AAAA) record(s)
Got: 2001:610:1a08:292:129:125:2:51
Info::
5 nameserver(s) configured
Got: dns3.rug.nl, dns2.rug.nl, ns2.surfnet.nl, dns1.rug.nl, ns1.surfnet.nl
Info::
5 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: 31 ms
Got: 31 ms
A129.125.2.51
AAAA2001:610:1a08:292:129:125:2:51
CNAME
NSdns3.rug.nl, dns2.rug.nl, ns2.surfnet.nl, dns1.rug.nl, ns1.surfnet.nl
MX
10 ASPMX.L.GOOGLE.COM
20 ALT1.ASPMX.L.GOOGLE.COM
20 ALT2.ASPMX.L.GOOGLE.COM
30 ASPMX3.GOOGLEMAIL.COM
30 ASPMX2.GOOGLEMAIL.COM
TXT
HARICA-iXUSYZelD4KghRtTA8V
University of Groningen
google-site-verification=LzOS5q7nSbDRZFZ0FMFKbWSvsfDE8bL861TAh-czT7k
MS=ms97484282
mistral-domain-verification=139d17efc022c67581effa2fc6e0bb747d0c9456
SPF v=spf1 include:spf1.rug.nl include:spf2.rug.nl include:spf3.rug.nl include:spf4....
bw=7iePWW2zaVtqaRhZZjRWUu985gQ1Ia26nUAJ3BDXMYBp
google-site-verification=pMjlXqlOTWrDjxV9AoW_MGyuGOV3lEAsQ7__vv525Ag
CAALookup not available with standard resolver
Resolved in 31 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://rug.nl → https://www.rug.nl/ (301)
Info::
WWW normalization redirect

https://rug.nl

109 ms · HTTP/1.0

301

https://www.rug.nl/

200 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://rug.nl301109 msHTTP/1.0BigIP
2https://www.rug.nl/200200 msHTTP/1.1

See the visual redirect chain in the HTTP Probe tab →

A+
IPv6 Readiness
IPv6 reachable (34 ms)
PASS
IPv6 reachable (34 ms)
Info::
IPv6 is configured and reachable at 2001:610:1a08:292:129:125:2:51
Got: 34 ms connect
IPv6 Ready
AAAA Records 2001:610:1a08:292:129:125:2:51 Connection Reachable (34 ms)
A+
Crawlability
robots.txt present, sitemap with 2 URLs
PASS
robots.txt present, sitemap with 2 URLs
Info::
robots.txt is present
Got: 715 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 2 entries
Info::
Sitemap index with 2 child sitemaps
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 715 B Sitemaps referenced 1 User-agents MagnetmeBot, * Blocking No — crawling allowed
User-agent: MagnetmeBot
Disallow: / 

User-agent: *
Disallow: /sciencelinx/blackholegame/index.html/robots.txt
Disallow: /_shared/
Disallow: /webvernieuwing/
Disallow: /forms/
Disallow: /*browseandselect
Disallow: /*browseAndSelect
Disallow: /*!find
Disallow: /*!mailTo
Disallow: /*!languagepreference
Disallow: /*!content
Disallow: /*!getAnalytics
Disallow: /*!rss
Disallow: /*!sso
Disallow: /*/old-research
Disallow: /society-business/centre-for-information-technology/organisation/pictogram/archief/
Disallow: /*?*pageSize=
Disallow: /*?*ordering=
Disallow: /*?*nofollow=true
Disallow: /*/concepts/
Disallow: /*.rss
Disallow: /*.xps
Disallow: /*hfid=

Sitemap: https://www.rug.nl/sitemaps/publicSitemapIndex.xml

sitemap.xml 200 OK
Type Sitemap Index URLs 2 entries Valid XML Yes
A+
Domain Intelligence
rug.nl — via Rijksuniversiteit Groningen, 38 years, 5 months old
PASS
rug.nl — via Rijksuniversiteit Groningen, 38 years, 5 months old
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: Rijksuniversiteit Groningen
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

223 days

Issued by Hellenic Academic and Research Institutions CA

Domain age

38 years, 5 months

Registered June 2, 1988

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

Unknown

2001:610:1a08:292:129:125:2:51

Registrar

Rijksuniversiteit Groningen

Unlocked 5 NS records
Expiry timeline
Today
+1 year
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 Rijksuniversiteit Groningen
Created June 2, 1988 (38 years, 5 months ago)
Last Updated December 16, 2025
Name Servers dns2.rug.nl, dns3.rug.nl, ns2.surfnet.nl, dns1.rug.nl, ns1.surfnet.nl
DNSSEC Not enabled
Registrant Rijksuniversiteit Groningen
Hosting
IP Address 2001:610:1a08:292:129:125:2:51
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 144 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
37 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.
40 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
145 ms
Total Time Total request time from DNS lookup through full response.
145 ms

Connection waterfall

DNS Lookup 37 ms TCP Connect 34 ms TLS Handshake 40 ms Server Processing 34 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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