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https://du.edu

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
90
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.du.edu/
200https://du.edu/

Inconsistent — duplicate content risk

HTTP → HTTPS

301http://du.edu/ → https://du.edu/

Consistent

B
TLS Certificate Expiry & Recommendations
81 days until leaf cert expires — 5 issues to address
REVIEW

Certificate validity

81
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 includeSubDomains to the HSTS directive
  • 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
1 A records, 603 ms lookup
PASS
1 A records, 603 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 23.185.0.1
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
Info::
Has 2 IPv6 (AAAA) record(s)
Got: 2620:12a:8001::1, 2620:12a:8000::1
Info::
4 nameserver(s) configured
Got: ns1.p201.dns.oraclecloud.net, ns3.p201.dns.oraclecloud.net, ns4.p201.dns.oraclecloud.net, ns2.p201.dns.oraclecloud.net
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
Warning::
DNS resolution is slow (603 ms)
Slow DNS adds latency to every page load. Consider a faster DNS provider.
Got: 603 ms
A23.185.0.1
AAAA2620:12a:8001::1, 2620:12a:8000::1
CNAME—
NSns1.p201.dns.oraclecloud.net, ns3.p201.dns.oraclecloud.net, ns4.p201.dns.oraclecloud.net, ns2.p201.dns.oraclecloud.net
MX
10 mxa-00241a02.gslb.pphosted.com
10 mxb-00241a02.gslb.pphosted.com
TXT
e2ma-verification=jzzfb
e2ma-verification=ql0eb
3uell7slaqp2luvba6no4mq9ah
google-site-verification=li-DPuVqdlxRew5Z-oVIcICDQix2K3J6b5uc5Egt6rc
autodesk-domain-verification=T1ZbSb-RI16TMKr4rKqI
facebook-domain-verification=4o143ljo7p1bpjzt0vsxrqalpvrmiq
_globalsign-domain-verification=ASEHzH085zgWDJZcOqX2IKb-tTYrTockt1-Jb-veYs
google-site-verification=vg5wRrG8iFFWuDwdUdEGtdYZEOva3a_3ESENnOt2Pzg
MS=ms18061669
intersight=42d79a3618a8843e27174d6405d1c1effacecef29f248ec259a1133d043b5c5a
v=DMARC1; p=quarantine; fo=1; rua=mailto:dmarc_rua@emaildefense.proofpoint.com; ...
d365mktkey=im5pAUiXm9IxDRIhSFTMCW8DrOqP2CFgh9WVIVjP6Ycx
ktD+DpsDo4zc7Q/sjuH9eSx3Ms0KbT7em+nmsfXd9w8w56exAd00lZOKiXma8Bss/v6xIcCoXNA6+wkk...
d365mktkey=oXlxTfVBvFPkBUs0GXSm8nlxexr6BtyotomfdOWpD3ox
asv=4d037429df1c38a629a2c2c1e9d75714
cisco-ci-domain-verification=7e7b24754d2adca3015b74d24204c80df1e6b95614294a8c889...
48tgv7bnpo320endltdp4qqpir
google-site-verification:WHNxr1IRt0U4trUGOx0P_3Mapbx4bAOGrvpzn6WTydY
adobe-idp-site-verification=fcc78d68a8825dbfa9937ca2e8cbb9823ad970f9a896ffe042d0...
pardot_149391_*=94d4b6541d12ae48c5b83aee5dc6a841a9c79040ae36f33cfda6edc4a3f2cbbc
docusign=1ff8210c-4b7c-463d-bf8d-dec467d3b6cc
drnsfqu81d70lsvsv5uoe6lsn7
google-site-verification=BEXpZiSjkKq5DyMW_NJO4HJozpNKhd-RFoZ1SU2AlZ0
docusign=b02d4133-de65-4905-aeb7-05ed5173b1ea
SPF v=spf1 ip4:54.173.83.138 ip4:107.23.16.222 ip4:130.253.1.71 ip4:130.253.1.193 ip...
CAALookup not available with standard resolver
Resolved in 603 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.

Slow DNS adds latency to every page load. Consider a faster DNS provider.

Why this matters

DNS resolution is slow — anycast DNS providers (Cloudflare, Route 53) typically resolve <50ms globally.

Source: DNS performance benchmarks

A
Redirect Chain
1 redirect(s), 178 ms total
PASS
1 redirect(s), 178 ms total
Info::
Single redirect
Got: https://du.edu → https://www.du.edu/ (301)
Info::
WWW normalization redirect

https://du.edu

7 ms · HTTP/1.1

301

https://www.du.edu/

171 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://du.edu3017 msHTTP/1.1nginx
2https://www.du.edu/200171 msHTTP/1.1nginx

See the visual redirect chain in the HTTP Probe tab →

A+
IPv6 Readiness
IPv6 reachable (0 ms)
PASS
IPv6 reachable (0 ms)
Info::
IPv6 is configured and reachable at 2620:12a:8001::1, 2620:12a:8000::1
Got: 0 ms connect
IPv6 Ready
AAAA Records 2620:12a:8001::1, 2620:12a:8000::1 Connection Reachable (0 ms)
A+
Crawlability
robots.txt present, sitemap with 2 URLs
PASS
robots.txt present, sitemap with 2 URLs
Info::
robots.txt is present
Got: 1706 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 2 entries
Info::
Sitemap index with 2 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 1706 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.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 Sitemap Index URLs 2 entries Valid XML Yes
Child Sitemaps:
A+
Domain Intelligence
du.edu — 38 years, 8 months old
PASS
du.edu — 38 years, 8 months old
Info::
Domain registered until Jul 31, 2027 (1 years, 3 months remaining)
Domain expiry

410 days

July 31, 2027

SSL certificate

81 days

Issued by Let's Encrypt

Domain age

38 years, 8 months

Registered February 25, 1988

DNSSEC

Status unknown

Protects against DNS spoofing

Hosting

Unknown

2620:12a:8001::1

Registrar

Registrar unknown

Lock status unknown 4 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Registrar
Created February 25, 1988 (38 years, 8 months ago)
Expires July 31, 2027 (1 years, 3 months)
Last Updated July 25, 2025
Name Servers ns4.p201.dns.oraclecloud.net, ns3.p201.dns.oraclecloud.net, ns2.p201.dns.oraclecloud.net, ns1.p201.dns.oraclecloud.net
Registrant University of Denver
Hosting
IP Address 2620:12a:8001::1
Data source: whois (0.8s)
A+
HTTP Probe Timing
Total 58 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
51 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.
58 ms
Total Time Total request time from DNS lookup through full response.
58 ms

Connection waterfall

DNS Lookup 51 ms TCP Connect 0 ms TLS Handshake 4 ms Server Processing 3 ms Content Transfer 0 ms
A+
CDN & Delivery
Fastly (HIT, HIT)
PASS
Fastly (HIT, HIT)
Info::
Site is served via Fastly CDN
Got: x-served-by: cache-chi-klot8100058-CHI, cache-toj-leto2350044-TOJ
Info::
CDN cache status: HIT, HIT
CDN Detected: Fastly
Provider Fastly Cache Status HIT, HIT Evidence x-served-by: cache-chi-klot8100058-CHI, cache-toj-leto2350044-TOJ
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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