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https://zenodo.org

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
97
GRADE
A+
FIX
1
REVIEW
1
PASS
7
INFO
0
Probed from Madrid, Spain
200 OK
Checks
9
7 PASS 1 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
TLS Certificate Expiry & Recommendations
Action
22 days until leaf cert expires — 4 issues to address
REVIEW

Certificate validity

22
days left
0d 30d 60d 90d+
Renew soon — under 30 days remaining

Recommended actions

  • Renew certificate — 22 days remaining
  • 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
6 A records, 30 ms lookup
PASS
6 A records, 30 ms lookup
Info::
Resolves to 6 IPv4 address(es)
Got: 188.184.103.118, 137.138.153.219, 188.184.98.114, 137.138.52.235, 188.185.48.75, 188.185.43.153
Info::
Has 6 IPv6 (AAAA) record(s)
Got: 2001:1458:d00:13::100:f2, 2001:1458:d00:3a::100:3da, 2001:1458:d00:3b::100:4d6, 2001:1458:d00:24::100:245, 2001:1458:d00:17::100:1d9, 2001:1458:d00:61::100:427
Info::
2 nameserver(s) configured
Got: albert.ns.cloudflare.com, surina.ns.cloudflare.com
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: 30 ms
Got: 30 ms
A188.184.103.118, 137.138.153.219, 188.184.98.114, 137.138.52.235, 188.185.48.75, 188.185.43.153
AAAA2001:1458:d00:13::100:f2, 2001:1458:d00:3a::100:3da, 2001:1458:d00:3b::100:4d6, 2001:1458:d00:24::100:245, 2001:1458:d00:17::100:1d9, 2001:1458:d00:61::100:427
CNAME—
NSalbert.ns.cloudflare.com, surina.ns.cloudflare.com
MX
10 cern-ch.mail.protection.outlook.com
TXT
MS=ms55096257
SPF v=spf1 include:spf.cern.ch include:smtp1.uservoice.com -all
google-site-verification=5fPGCLllnWrvFxH9QWI0l1TadV7byeEvfPcyK2VkS_s
CAALookup not available with standard resolver
Resolved in 30 ms

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://zenodo.org

https://zenodo.org

109 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://zenodo.org200109 msHTTP/1.1nginx
A+
IPv6 Readiness
IPv6 reachable (33 ms)
PASS
IPv6 reachable (33 ms)
Info::
IPv6 is configured and reachable at 2001:1458:d00:13::100:f2, 2001:1458:d00:3a::100:3da, 2001:1458:d00:3b::100:4d6, 2001:1458:d00:24::100:245, 2001:1458:d00:17::100:1d9, 2001:1458:d00:61::100:427
Got: 33 ms connect
IPv6 Ready
AAAA Records 2001:1458:d00:13::100:f2, 2001:1458:d00:3a::100:3da, 2001:1458:d00:3b::100:4d6, 2001:1458:d00:24::100:245, 2001:1458:d00:17::100:1d9, 2001:1458:d00:61::100:427 Connection Reachable (33 ms)
A+
Crawlability
robots.txt present, sitemap with 595 URLs
PASS
robots.txt present, sitemap with 595 URLs
Info::
robots.txt is present
Got: 233 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 595 entries
Info::
Sitemap index with 595 child sitemaps
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 233 B Sitemaps referenced 0 User-agents * Blocking No — crawling allowed
User-agent: *
Disallow: /search
Disallow: /api
Disallow: /administration
Disallow: /account
Disallow: /uploads
Disallow: /me
Disallow: /login
Disallow: /logout
Disallow: /records/*/preview
Allow: /api/records/*/files
Crawl-delay: 10
sitemap.xml 200 OK
Type Sitemap Index URLs 595 entries Valid XML Yes
Child Sitemaps:
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

301https://www.zenodo.org/
200https://zenodo.org/

Preferred variant: non-www

HTTP → HTTPS

302http://zenodo.org/ → https://zenodo.org/

Use 301 (permanent) instead of 302 (temporary)

A+
Domain Intelligence
zenodo.org — via CSC Corporate Domains, Inc., 13 years, 7 months old
PASS
zenodo.org — via CSC Corporate Domains, Inc., 13 years, 7 months old
Info::
Domain registered until Nov 15, 2026 (6 months remaining)
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: CSC Corporate Domains, Inc.
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

152 days

November 15, 2026

SSL certificate

22 days

Issued by Sectigo Limited

Domain age

13 years, 7 months

Registered November 15, 2012

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

Unknown

2001:1458:d00:13::100:f2

Registrar

CSC Corporate Domains, Inc.

Unlocked 2 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Recommended actions
  • Renew the TLS certificate or verify auto-renewal is working
  • Enable DNSSEC to protect visitors from DNS spoofing
  • Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
Registrar CSC Corporate Domains, Inc.
Created November 15, 2012 (13 years, 7 months ago)
Expires November 15, 2026 (6 months)
Last Updated November 16, 2025
Name Servers albert.ns.cloudflare.com, surina.ns.cloudflare.com
DNSSEC Not enabled
Hosting
IP Address 2001:1458:d00:13::100:f2
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 181 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
44 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
31 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
34 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
150 ms
Total Time Total request time from DNS lookup through full response.
181 ms

Connection waterfall

DNS Lookup 44 ms TCP Connect 31 ms TLS Handshake 34 ms Server Processing 41 ms Content Transfer 31 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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