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https://cuni.cz

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
98
GRADE
A+
FIX
1
REVIEW
2
PASS
6
INFO
0
Probed from Singapore, Singapore
200 OK
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
HTTP Probe Timing
Action
Total 1925 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
REVIEW
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
175 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
169 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
172 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
1.92 s
Total Time Total request time from DNS lookup through full response.
1.93 s

Connection waterfall

DNS Lookup 175 ms TCP Connect 169 ms TLS Handshake 172 ms Server Processing 1.41 s Content Transfer 1 ms
B
TLS Certificate Expiry & Recommendations
125 days until leaf cert expires — 3 issues to address
REVIEW

Certificate validity

125
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 OCSP stapling on your TLS server to remove a CA roundtrip and protect user privacy
A+
DNS Records
1 A records, 180 ms lookup
PASS
1 A records, 180 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 195.113.89.54
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: 2001:718:1e03:622::60
Info::
4 nameserver(s) configured
Got: nsa.ces.net, cuce.ruk.cuni.cz, david.ruk.cuni.cz, golias.ruk.cuni.cz
Info::
2 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: 180 ms
Got: 180 ms
A195.113.89.54
AAAA2001:718:1e03:622::60
CNAME—
NSnsa.ces.net, cuce.ruk.cuni.cz, david.ruk.cuni.cz, golias.ruk.cuni.cz
MX
10 ag1.cesnet.cz
10 ag2.cesnet.cz
TXT
google-site-verification=52QIa-wnhi8U3xyitTyH9czyXoo3OkkFbqzAJW7U5HM
google-site-verification=LazYVCEv9A_edcp-AQV8RBrOcYmEyvoC1t68iOp7tSI
google-site-verification=T4H_GYV-wpMp1W0zdIt62whR5pTIIr9HOSoS75qomrs
SPF v=spf1 ip6:2001:718:1e03:4::16 a:out.ruk.cuni.cz a:dec59.ruk.cuni.cz a:golias.ru...
CAALookup not available with standard resolver
Resolved in 180 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://cuni.cz

https://cuni.cz

1139 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://cuni.cz2001139 msHTTP/1.1nginx
A+
IPv6 Readiness
IPv6 reachable (154 ms)
PASS
IPv6 reachable (154 ms)
Info::
IPv6 is configured and reachable at 2001:718:1e03:622::60
Got: 154 ms connect
IPv6 Ready
AAAA Records 2001:718:1e03:622::60 Connection Reachable (154 ms)
A+
Crawlability
robots.txt present, sitemap with 630 URLs
PASS
robots.txt present, sitemap with 630 URLs
Info::
robots.txt is present
Got: 23 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 630 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 23 B Sitemaps referenced 0 User-agents * Blocking No — crawling allowed
User-agent: *
Disallow:
sitemap.xml 200 OK
Type URL Set URLs 630 entries Valid XML Yes
Sample URLs:
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.cuni.cz/
200https://cuni.cz/

Preferred variant: non-www

HTTP → HTTPS

301http://cuni.cz/ → https://cuni.cz/

Consistent

A+
Domain Intelligence
cuni.cz — via REG-INTERNET-CZ, 30 years, 6 months old
PASS
cuni.cz — via REG-INTERNET-CZ, 30 years, 6 months old
Info::
Domain registered until Oct 9, 2034 (8 years, 7 months remaining)
Info::
DNSSEC is enabled
Info::
Registrar: REG-INTERNET-CZ
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

2976 days

October 9, 2034

SSL certificate

125 days

Issued by Hellenic Academic and Research Institutions CA

Domain age

30 years, 6 months

Registered March 10, 1996

DNSSEC

Enabled

Protects against DNS spoofing

Hosting

Unknown

2001:718:1e03:622::60

Registrar

REG-INTERNET-CZ

Unlocked 4 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Recommended actions
  • Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
Registrar REG-INTERNET-CZ
Created March 10, 1996 (30 years, 6 months ago)
Expires October 9, 2034 (8 years, 7 months)
Last Updated December 31, 2024
Name Servers cuce.ruk.cuni.cz, david.ruk.cuni.cz, golias.ruk.cuni.cz, nsa.ces.net
DNSSEC Enabled
Hosting
IP Address 2001:718:1e03:622::60
Data source: rdap (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

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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