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https://ens.fr

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 Amsterdam, Netherlands
301 Moved Permanently
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, sitemap with 3071 URLs
REVIEW
robots.txt present, sitemap with 3071 URLs
Info::
robots.txt is present
Got: 2027 bytes
Info::
sitemap.xml is present
Warning::
sitemap.xml contains invalid XML
Search engines may not be able to parse the sitemap. Fix XML validation errors.
Info::
sitemap.xml contains 3071 entries
Info::
robots.txt does not reference a sitemap
Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

Search engines may not be able to parse the sitemap. Fix XML validation errors.

Why this matters

An unparseable sitemap is silently ignored by Google — the URLs it advertises are never queued for crawl.

Learn more ▾

Google's sitemap parser is strict about XML validity. A single unescaped `&` or unclosed tag invalidates the whole file. Run your sitemap through a validator (Search Console's Sitemaps report flags it) and fix the offending entry. Most generators escape correctly; mistakes usually come from manually-written entries.

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 2027 B Sitemaps referenced 0 User-agents * Blocking No — crawling allowed
#
# robots.txt
#
# This file is to prevent the crawling and indexing of certain parts
# of your site by web crawlers and spiders run by sites like Yahoo!
# and Google. By telling these "robots" where not to go on your site,
# you save bandwidth and server resources.
#
# This file will be ignored unless it is at the root of your host:
# Used:    http://example.com/robots.txt
# Ignored: http://example.com/site/robots.txt
#
# For more information about the robots.txt standard, see:
# http://www.robotstxt.org/robotstxt.html

User-agent: *
# CSS, JS, Images
Allow: /core/*.css$
Allow: /core/*.css?
Allow: /core/*.js$
Allow: /core/*.js?
Allow: /core/*.gif
Allow: /core/*.jpg
Allow: /core/*.jpeg
Allow: /core/*.png
Allow: /core/*.svg
Allow: /profiles/*.css$
Allow: /profiles/*.css?
Allow: /profiles/*.js$
Allow: /profiles/*.js?
Allow: /profiles/*.gif
Allow: /profiles/*.jpg
Allow: /profiles/*.jpeg
Allow: /profiles/*.png
Allow: /profiles/*.svg
# Directories
Disallow: /core/
Disallow: /profiles/
# Files
Disallow: /README.md
Disallow: /composer/Metapackage/README.txt
Disallow: /composer/Plugin/ProjectMessage/README.md
Disallow: /composer/Plugin/Scaffold/README.md
Disallow: /composer/Plugin/VendorHardening/README.txt
Disallow: /composer/Template/README.txt
Disallow: /modules/README.txt
Disallow: /sites/README.txt
Disallow: /themes/README.txt
Disallow: /web.config
# Paths (clean URLs)
Disallow: /admin/
Disallow: /comment/reply/
Disallow: /filter/tips
Disallow: /node/add/
Disallow: /search/
Disallow: /user/register
Disallow: /user/password
Disallow: /user/login
Disallow: /user/logout
Disallow: /media/oembed
Disallow: /*/media/oembed
# Paths (no clean URLs)
Disallow: /index.php/admin/
Disallow: /index.php/comment/reply/
Disallow: /index.php/filter/tips
Disallow: /index.php/node/add/
Disallow: /index.php/search/
Disallow: /index.php/user/password
Disallow: /index.php/user/register
Disallow: /index.php/user/login
Disallow: /index.php/user/logout
Disallow: /index.php/media/oembed
Disallow: /index.php/*/media/oembed
sitemap.xml 200 OK
Type URL Set URLs 3071 entries Valid XML No
Sample URLs:
B
TLS Certificate Expiry & Recommendations
169 days until leaf cert expires — 4 issues to address
REVIEW

Certificate validity

169
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 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
2 A records, 35 ms lookup
PASS
2 A records, 35 ms lookup
Info::
Resolves to 2 IPv4 address(es)
Got: 129.199.166.212, 129.199.166.211
Info::
No IPv6 (AAAA) records
Info::
5 nameserver(s) configured
Got: ns2.nic.fr, ns1.ens.fr, ns2.ens.fr, ext.lri.fr, ns.ens.fr
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: 35 ms
Got: 35 ms
A129.199.166.212, 129.199.166.211
AAAA—
CNAME—
NSns2.nic.fr, ns1.ens.fr, ns2.ens.fr, ext.lri.fr, ns.ens.fr
MX
10 mx2.relay.renater.fr
10 mx1.relay.renater.fr
TXT
apple-domain-verification=dLqshYXme7ZxLNGC
SPF v=spf1 mx ip4:129.199.96.32/28 ip4:129.199.96.3 ip4:5.135.56.216 include:spf.rel...
HARICA-3TqNrgHLQxGMBm58MbN
MS=ms47118652
google-site-verification=htti69mp2Mpt7vhxWUyefNCWwcYttyzSL5a6kmcoxRs
CAALookup not available with standard resolver
Resolved in 35 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
1 redirect(s), 177 ms total
PASS
1 redirect(s), 177 ms total
Info::
Single redirect
Got: https://ens.fr → https://www.ens.psl.eu/ (301)
Info::
WWW normalization redirect
Info::
Cross-domain redirect detected

https://ens.fr

84 ms · HTTP/1.1

301

https://www.ens.psl.eu/

93 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://ens.fr30184 msHTTP/1.1Apache
2https://www.ens.psl.eu/20093 msHTTP/1.1Apache/2.4.66

See the visual redirect chain in the HTTP Probe tab →

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

301https://www.ens.fr/
200https://ens.fr/

Preferred variant: non-www

HTTP → HTTPS

301http://ens.fr/ → https://ens.psl.eu/

Consistent

A+
Domain Intelligence
ens.fr — via GIP RENATER, 31 years, 9 months old, hosted on FR-RENATER Reseau National de telecommunications pour la Technologie, FR
PASS
ens.fr — via GIP RENATER, 31 years, 9 months old, hosted on FR-RENATER Reseau National de telecommunications pour la Technologie, FR
Info::
Domain registered until Dec 31, 2026 (8 months remaining)
Info::
Registrar: GIP RENATER
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: FR-RENATER Reseau National de telecommunications pour la Technologie, FR
Got: AS2200
Domain expiry

199 days

December 31, 2026

SSL certificate

169 days

Issued by Hellenic Academic and Research Institutions CA

Domain age

31 years, 9 months

Registered December 31, 1994

DNSSEC

Status unknown

Protects against DNS spoofing

Hosting

FR-RENATER Reseau National de telecommunications pour la Technologie, FR

ASN AS2200

129.199.166.211

Registrar

GIP RENATER

Unlocked 5 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 GIP RENATER
Created December 31, 1994 (31 years, 9 months ago)
Expires December 31, 2026 (8 months)
Last Updated January 31, 2026
Name Servers ext.lri.fr, ns.ens.fr, ns1.ens.fr, ns2.ens.fr, ns2.nic.fr
Registrant ECOLE NORMALE SUPERIEURE
Hosting
IP Address 129.199.166.211
ASN AS2200 (FR-RENATER Reseau National de telecommunications pour la Technologie, FR)
Provider FR-RENATER Reseau National de telecommunications pour la Technologie, FR
Data source: rdap (0.4s)

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

Connection waterfall

DNS Lookup 32 ms TCP Connect 14 ms TLS Handshake 23 ms Server Processing 14 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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