Skip to content
https://colorado.edu

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
93
GRADE
A
FIX
0
REVIEW
2
PASS
7
INFO
0
Probed from Madrid, Spain
301 Moved Permanently
Checks
9
7 PASS 2 REVIEW
B
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
REVIEW
www/non-www, trailing slash, HTTP→HTTPS
Critical::
Both www and non-www versions serve content
Got: Both variants return 200 Expected: One variant 301-redirects to the other
Info::
HTTP correctly 301-redirects to HTTPS

www / non-www

200https://www.colorado.edu/
200https://colorado.edu/

Inconsistent — duplicate content risk

HTTP → HTTPS

301http://colorado.edu/ → https://colorado.edu/

Consistent

C
TLS Certificate Expiry & Recommendations
Action
24 days until leaf cert expires — 6 issues to address
REVIEW

Certificate validity

24
days left
0d 30d 60d 90d+
Renew soon — under 30 days remaining

Recommended actions

  • Renew certificate — 24 days remaining
  • 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 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
4 A records, 43 ms lookup
PASS
4 A records, 43 ms lookup
Info::
Resolves to 4 IPv4 address(es)
Got: 151.101.2.133, 151.101.194.133, 151.101.130.133, 151.101.66.133
Info::
Has 4 IPv6 (AAAA) record(s)
Got: 2a04:4e42:600::645, 2a04:4e42:200::645, 2a04:4e42:400::645, 2a04:4e42::645
Info::
6 nameserver(s) configured
Got: a3-66.akam.net, a2-67.akam.net, a11-66.akam.net, a20-65.akam.net, a1-153.akam.net, a22-67.akam.net
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: 43 ms
Got: 43 ms
A151.101.2.133, 151.101.194.133, 151.101.130.133, 151.101.66.133
AAAA2a04:4e42:600::645, 2a04:4e42:200::645, 2a04:4e42:400::645, 2a04:4e42::645
CNAME—
NSa3-66.akam.net, a2-67.akam.net, a11-66.akam.net, a20-65.akam.net, a1-153.akam.net, a22-67.akam.net
MX
10 colorado-edu.mail.protection.outlook.com
TXT
brevo-code:ac843dd83e2d2a3d8becd980f7193d9b
jamf-site-verification=V7i5P5-QM02gTP25eIhZIA
atlassian-sending-domain-verification=0b36ce8f-b8ec-42ae-8513-2264ea6d72e7
_3x6w07ujdy2wk71two4k8r4mwmtw6tq
openai-domain-verification=dv-5hwuyXiWaOnaq12vb3n73azV
yahoo-verification-key=LBMWN06qx3V2Edw1euv/698yUrWMNip2Dx3Y4yyVmYE=
docusign=7412fd08-3676-471a-8b65-8cc2b13c8137
d365mktkey=CgcAzx2nkxamTBkNT7jagrT8Nadf6LPzlI0MLQHdKA0x
docusign=dcb8d5d8-71e8-4884-8604-02297bea8072
google-site-verification=iaVX54MaxYscXlrL-DxuE9qtvLhAXkXKhG8sjiH5q-0
atlassian-domain-verification=QAg9aEn1gpS7HapLhSZbdUei9wTKTCl8EKYsTFg5su7bO2Pu30...
brevo-code:5f9e8714a4a7c561eb4cdf0848811c11
SPF v=spf1 ip4:128.138.1.0/24 ip4:128.138.48.0/20 ip4:128.138.64.0/18 ip4:128.138.12...
brevo-code:814ad43e9f25b1a52d6a2b213fcfae73
d365mktkey=gzYMp5Xcnapx0VINCqRrvMtsD0TBSpLsrFjihN9HWQAx
bMFGPNmrr7aoZsBWqexbujPiPjVzJe4wrZfl/t81eGptVxvkprdRSqKfj3paVrFcRhsrQHBlMGIR86eX...
brevo-code:d6b523305300718643a7da77b3feeccb
MS=ms27269994
bw=E1ibKK7mvTTWmq1SV+b/usJyVdN63EU+WFJh+SCp+abE
CAALookup not available with standard resolver
Resolved in 43 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), 44 ms total
PASS
1 redirect(s), 44 ms total
Info::
Single redirect
Got: https://colorado.edu → https://www.colorado.edu/ (301)
Info::
WWW normalization redirect

https://colorado.edu

9 ms · HTTP/1.1

301

https://www.colorado.edu/

36 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://colorado.edu3019 msHTTP/1.1Varnish
2https://www.colorado.edu/20036 msHTTP/1.1nginx

See the visual redirect chain in the HTTP Probe tab →

A+
IPv6 Readiness
IPv6 reachable (1 ms)
PASS
IPv6 reachable (1 ms)
Info::
IPv6 is configured and reachable at 2a04:4e42:600::645, 2a04:4e42:200::645, 2a04:4e42:400::645, 2a04:4e42::645
Got: 1 ms connect
IPv6 Ready
AAAA Records 2a04:4e42:600::645, 2a04:4e42:200::645, 2a04:4e42:400::645, 2a04:4e42::645 Connection Reachable (1 ms)
A+
Crawlability
robots.txt present, sitemap with 1406 URLs
PASS
robots.txt present, sitemap with 1406 URLs
Info::
robots.txt is present
Got: 2005 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 1406 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 2005 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
# 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 1406 entries Valid XML Yes
Sample URLs:
A+
Domain Intelligence
colorado.edu — 40 years, 5 months old
PASS
colorado.edu — 40 years, 5 months old
Info::
Domain registered until Jul 31, 2026 (3 months remaining)
Domain expiry

16 days

July 31, 2026

SSL certificate

24 days

Issued by Certainly

Domain age

40 years, 5 months

Registered June 2, 1986

DNSSEC

Status unknown

Protects against DNS spoofing

Hosting

Unknown

2a04:4e42:200::645

Registrar

Registrar unknown

Lock status unknown 6 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Recommended actions
  • Renew the domain or enable auto-renewal to prevent accidental expiry
  • Renew the TLS certificate or verify auto-renewal is working
Registrar
Created June 2, 1986 (40 years, 5 months ago)
Expires July 31, 2026 (3 months)
Last Updated July 25, 2025
Name Servers a3-66.akam.net, a1-153.akam.net, a20-65.akam.net, a2-67.akam.net, a22-67.akam.net, a11-66.akam.net
Registrant University of Colorado
Hosting
IP Address 2a04:4e42:200::645
Data source: whois (0.8s)
A+
HTTP Probe Timing
Total 33 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
28 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
0 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
4 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
33 ms
Total Time Total request time from DNS lookup through full response.
33 ms

Connection waterfall

DNS Lookup 28 ms TCP Connect 0 ms TLS Handshake 4 ms Server Processing 1 ms Content Transfer 0 ms
A+
CDN & Delivery
Fastly (HIT)
PASS
Fastly (HIT)
Info::
Site is served via Fastly CDN
Got: x-served-by: cache-toj-leto2350075-TOJ
Info::
CDN cache status: HIT
CDN Detected: Fastly
Provider Fastly Cache Status HIT Evidence x-served-by: cache-toj-leto2350075-TOJ
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

Send Feedback