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https://rwth-aachen.de

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
93
GRADE
A
FIX
1
REVIEW
2
PASS
6
INFO
0
Probed from Madrid, Spain
302 Found
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.

B
Redirect Chain
2 redirect(s), 769 ms total
REVIEW
2 redirect(s), 769 ms total
Warning::
2 redirects before reaching final URL
Each redirect adds latency. Try to minimize the chain to 1 hop.
Info::
WWW normalization redirect
Info::
Uses 302 (temporary) redirect
If permanent, use 301 instead.
Got: https://rwth-aachen.de
Info::
Redirect overhead: 769 ms total
Got: 769 ms

https://rwth-aachen.de

230 ms · HTTP/1.1

302

https://rwth-aachen.de/go/id/a/?lidx=1

222 ms · HTTP/1.1

301

https://www.rwth-aachen.de/cms/~a/root/?...

317 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://rwth-aachen.de302230 msHTTP/1.1
2https://rwth-aachen.de/go/id/a/?lidx=1301222 msHTTP/1.1
3https://www.rwth-aachen.de/cms/~a/root/?...200317 msHTTP/1.1

See the visual redirect chain in the HTTP Probe tab →

Each redirect adds latency. Try to minimize the chain to 1 hop.

Why this matters

Redirect chain — each hop adds latency; combine into one redirect where possible.

Source: Google Search Central / web.dev

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

B
TLS Certificate Expiry & Recommendations
170 days until leaf cert expires — 6 issues to address
REVIEW

Certificate validity

170
days left
0d 30d 60d 90d+

Recommended actions

  • Prefer TLS 1.3 — TLS 1.2 is acceptable but TLS 1.3 removes RSA key exchange and improves latency
  • 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, 36 ms lookup
PASS
1 A records, 36 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 137.226.107.60
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: 2a00:8a60:450::107:60
Info::
4 nameserver(s) configured
Got: zs1.rz.rwth-aachen.de, zs2.rz.rwth-aachen.de, dns-1.dfn.de, dns-2.dfn.de
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: 36 ms
Got: 36 ms
A137.226.107.60
AAAA2a00:8a60:450::107:60
CNAME
NSzs1.rz.rwth-aachen.de, zs2.rz.rwth-aachen.de, dns-1.dfn.de, dns-2.dfn.de
MX
10 mx1.rz.rwth-aachen.de
TXT
SPF v=spf1 include:_spf.itc.rwth-aachen.de -all
adobe-idp-site-verification=f776e93b43310d11ffce240aee50080562eb76f499439e8f27f9...
google-gws-recovery-domain-verification=68268798
google-site-verification=MBo5UfSByZyIAyjv3TI4YpeIF3k9800b6R-0RuupVog
CAALookup not available with standard resolver
Resolved in 36 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+
IPv6 Readiness
IPv6 reachable (29 ms)
PASS
IPv6 reachable (29 ms)
Info::
IPv6 is configured and reachable at 2a00:8a60:450::107:60
Got: 29 ms connect
IPv6 Ready
AAAA Records 2a00:8a60:450::107:60 Connection Reachable (29 ms)
A+
Crawlability
robots.txt present, sitemap with 5484 URLs
PASS
robots.txt present, sitemap with 5484 URLs
Info::
robots.txt is present
Got: 36 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 5484 entries
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 36 B Sitemaps referenced 0 User-agents * Blocking No — crawling allowed
#custom

User-agent: *

Disallow: 


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)
Info::
HTTP correctly 301-redirects to HTTPS

www / non-www

302https://www.rwth-aachen.de/
200https://rwth-aachen.de/

Preferred variant: non-www

HTTP → HTTPS

301http://rwth-aachen.de/ https://rwth-aachen.de/

Consistent

A+
Domain Intelligence
rwth-aachen.de
PASS
rwth-aachen.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.
Domain expiry

Unknown

SSL certificate

170 days

Issued by Hellenic Academic and Research Institutions CA

Domain age

Unknown

DNSSEC

Status unknown

Protects against DNS spoofing

Hosting

Unknown

2a00:8a60:450::107:60

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 2a00:8a60:450::107:60
Data source: whois (0.6s)

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 261 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.
36 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
123 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
261 ms
Total Time Total request time from DNS lookup through full response.
262 ms

Connection waterfall

DNS Lookup 34 ms TCP Connect 36 ms TLS Handshake 123 ms Server Processing 68 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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