Infrastructure
· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.DCDN & DeliveryActionNo CDN detectedFIX
Consider using a CDN to improve global delivery speed and reduce origin load.
CIPv6 ReadinessActionNo IPv6 supportREVIEW
IPv6 support is increasingly important for global accessibility. About 40% of internet users have IPv6 connectivity.
No AAAA records — same impact as 'no IPv6 (AAAA) records'; IPv6-preferring clients pay extra latency falling back to IPv4.
Source: Google IPv6 stats
BURL Variantswww/non-www, trailing slash, HTTP→HTTPSREVIEW
www / non-www
Inconsistent — duplicate content risk
HTTP → HTTPS
Consistent
BTLS Certificate Expiry & Recommendations76 days until leaf cert expires — 3 issues to addressREVIEW
Certificate validity
Recommended actions
- Enable HSTS: Strict-Transport-Security: max-age=31536000; includeSubDomains
- 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 Records1 A records, 37 ms lookupPASS
| A | 134.100.36.8 |
| AAAA | — |
| CNAME | — |
| NS | dns-3.dfn.de, ns.rrz.uni-hamburg.de, rzdspc1.informatik.uni-hamburg.de, dns2.rrz.uni-hamburg.de, dns1.rrz.uni-hamburg.de |
| MX | 5 mx05.rrz.uni-hamburg.de 5 mx04.rrz.uni-hamburg.de 5 mx03.rrz.uni-hamburg.de |
| TXT | google-site-verification=OZcUjRiXyV-FC_CETAcSW8vmGy5Z5PVeV9VuY6hmmPk jamf-site-verification=myEv21-oaE8vC4h52sT0-A apple-domain-verification=EOZVdX53PEO7QreC HARICA-Ni6eI7VbLz7zJSPBbY4 adobe-idp-site-verification=46b245589c136af9a25e6fe7e169e3f2256cae02b6e3b087d82c... MS=442ABFBA9905F38423AE1FC75712741886F34779 SPF v=spf1 ip4:134.100.38.64/26 ~all google-gws-recovery-domain-verification=53008832 |
| CAA | Lookup not available with standard resolver |
Multiple A records provide failover if one server goes down.
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.
Informational: CAA (Certification Authority Authorization) records weren't checked in this scan.
ARedirect Chain1 redirect(s), 737 ms totalPASS
https://uni-hamburg.de
376 ms · HTTP/1.1
https://www.uni-hamburg.de/
361 ms · HTTP/1.1 FINAL
| # | URL | Status | Time | Protocol | Server |
|---|---|---|---|---|---|
| 1 | https://uni-hamburg.de | 301 | 376 ms | HTTP/1.1 | Apache/2.4.41 (Ubuntu) |
| 2 | https://www.uni-hamburg.de/ | 200 | 361 ms | HTTP/1.1 | Apache/2.4.41 (Ubuntu) |
See the visual redirect chain in the HTTP Probe tab →
A+Crawlabilityrobots.txt present, sitemap with 333 URLsPASS
Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.
robots.txt omits Sitemap: directive — crawlers must fetch /sitemap.xml by convention; reliable but missing the explicit hint.
Source: sitemaps.org
User-agent: *
Disallow: /onTEAM/admin/*.htm$
Disallow: /onTEAM/admin/*.html$
Disallow: /Shibboleth.sso/
Disallow: /impressum-reservierung*
Disallow: /de/impressum-reservierung*
Disallow: /en/impressum-reservierung*
A+Domain Intelligenceuni-hamburg.de — hosted on DFN Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DEPASS
Unknown
76 days
Issued by Let's Encrypt
Unknown
Status unknown
Protects against DNS spoofing
DFN Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE
ASN AS680
134.100.36.8
Registrar unknown
Expiry timeline
Recommended actions
- Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
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.
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