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https://tu-dresden.de

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
87
GRADE
B
FIX
1
REVIEW
3
PASS
5
INFO
0
Probed from Madrid, Spain
200 OK
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
Crawlability
robots.txt present, no sitemap
REVIEW
robots.txt present, no sitemap
Info::
robots.txt is present
Got: 545 bytes
Info::
No sitemap.xml found
A sitemap helps search engines discover and index your pages more efficiently.
Info::
robots.txt does not reference a sitemap
Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

A sitemap helps search engines discover and index your pages more efficiently.

Why this matters

No sitemap.xml — Google relies on crawl-graph discovery alone, slowing indexing of deep or fresh URLs.

Learn more

A sitemap accelerates Google's discovery of new and updated content. Most CMSes auto-generate one; static-site frameworks need a build-step plugin. Reference it from robots.txt and submit in Search Console to confirm Google can fetch it.

Source: sitemaps.org / Google Search Central

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 545 B Sitemaps referenced 0 User-agents * Blocking No — crawling allowed
User-agent: *
Disallow: /@@search$
Disallow: /@@search?
Disallow: /*/@@search$
Disallow: /*/@@search?
Disallow: /search$
Disallow: /search?
Disallow: /*/search$
Disallow: /*/search?
Disallow: /RSS$
Disallow: /RSS?
Disallow: /*/RSS$
Disallow: /*/RSS?
Disallow: /rss.xml$
Disallow: /rss.xml?
Disallow: /*/rss.xml$
Disallow: /*/rss.xml?
Disallow: /atom.xml$
Disallow: /atom.xml?
Disallow: /*/atom.xml$
Disallow: /*/atom.xml?
Disallow: /ics_view$
Disallow: /ics_view?
Disallow: /*/ics_view$
Disallow: /*/ics_view?
Disallow: /Shibboleth.sso/
        
sitemap.xml No sitemap found

No sitemap found

Adding a sitemap helps search engines discover your pages.

B
TLS Certificate Expiry & Recommendations
189 days until leaf cert expires — 5 issues to address
REVIEW

Certificate validity

189
days left
0d 30d 60d 90d+

Recommended actions

  • Extend HSTS max-age to at least 31536000 (1 year) to meet the preload list criteria
  • 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, 48 ms lookup
PASS
1 A records, 48 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 141.76.14.10
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
Info::
No IPv6 (AAAA) records
Info::
4 nameserver(s) configured
Got: dns-1.dfn.de, dns-3.dfn.de, adns1.zih.tu-dresden.de, adns2.zih.tu-dresden.de
Info::
3 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: 48 ms
Got: 48 ms
A141.76.14.10
AAAA
CNAME
NSdns-1.dfn.de, dns-3.dfn.de, adns1.zih.tu-dresden.de, adns2.zih.tu-dresden.de
MX
10 a3011.mx.srv.dfn.de
10 c3011.mx.srv.dfn.de
10 b3011.mx.srv.dfn.de
TXT
lnk_sndcpt_00fca03d274327a135473e33e07996dd
ZOOM_verify_BknoIvsqjs9bXO0MErTgyw
SPF v=spf1 include:_spf.zih.tu-dresden.de include:_spf.o301.mx.srv.dfn.de include:_s...
google-site-verification=DGZkuR23xCSStevwpTamkYn6UhvzY8i_KmG3AnopG5Y
adobe-idp-site-verification=6e2dfc8c175f7d874197fdee6fd92985d1f52f826a486a6e9b95...
MS=D5C91E3A539F983C73A5FCFA8FCF7195ADAD6D7E
CAALookup not available with standard resolver
Resolved in 48 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
No redirects — direct access
PASS
No redirects — direct access
Info::
No redirects — direct access
Got: https://tu-dresden.de

https://tu-dresden.de

190 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://tu-dresden.de200190 msHTTP/1.1nginx
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: non-www)
Warning::
HTTP→HTTPS redirect uses 302 instead of 301
Got: 302 temporary redirect Expected: 301 permanent redirect

www / non-www

302https://www.tu-dresden.de/
200https://tu-dresden.de/

Preferred variant: non-www

HTTP → HTTPS

302http://tu-dresden.de/ https://tu-dresden.de/

Use 301 (permanent) instead of 302 (temporary)

A+
Domain Intelligence
tu-dresden.de — hosted on DFN Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE
PASS
tu-dresden.de — hosted on DFN Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE
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: DFN Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE
Got: AS680
Domain expiry

Unknown

SSL certificate

189 days

Issued by Hellenic Academic and Research Institutions CA

Domain age

Unknown

DNSSEC

Status unknown

Protects against DNS spoofing

Hosting

DFN Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE

ASN AS680

141.76.14.10

Registrar

Registrar unknown

Unlocked Name servers unknown
Expiry timeline
Today
+1 year
SSL expiry Danger zone (≤30 days)
Recommended actions
  • Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
Registrar
Hosting
IP Address 141.76.14.10
ASN AS680 (DFN Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE)
Provider DFN Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE
Data source: whois (0.7s)

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

Connection waterfall

DNS Lookup 45 ms TCP Connect 37 ms TLS Handshake 42 ms Server Processing 75 ms Content Transfer 35 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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