Skip to content
https://cmu.edu

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
80
GRADE
B
FIX
1
REVIEW
4
PASS
4
INFO
0
Probed from Madrid, Spain
301 Moved Permanently
Checks
9
4 PASS 4 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.

B
Redirect Chain
1 redirect(s), 1177 ms total
REVIEW
1 redirect(s), 1177 ms total
Info::
Single redirect
Got: https://cmu.edu → https://www.cmu.edu/ (301)
Info::
WWW normalization redirect
Warning::
Redirect overhead: 1177 ms total
Got: 1177 ms

https://cmu.edu

416 ms · HTTP/1.0

301

https://www.cmu.edu/

762 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://cmu.edu301416 msHTTP/1.0BigIP
2https://www.cmu.edu/200762 msHTTP/1.1nginx

See the visual redirect chain in the HTTP Probe tab →

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
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.cmu.edu/
200https://cmu.edu/

Inconsistent — duplicate content risk

HTTP → HTTPS

301http://cmu.edu/ → https://cmu.edu/

Consistent

B
TLS Certificate Expiry & Recommendations
272 days until leaf cert expires — 4 issues to address
REVIEW

Certificate validity

272
days left
0d 30d 60d 90d+

Recommended actions

  • Prefer TLS 1.3 — TLS 1.2 is acceptable but TLS 1.3 removes RSA key exchange and improves latency
  • Enable HSTS: Strict-Transport-Security: max-age=31536000; includeSubDomains
  • 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, 314 ms lookup
PASS
1 A records, 314 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 128.2.42.10
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
Info::
No IPv6 (AAAA) records
Info::
3 nameserver(s) configured
Got: NSAUTH3.NET.cmu.edu, NSAUTH2.NET.cmu.edu, NSAUTH1.NET.cmu.edu
Info::
5 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 (314 ms)
Slow DNS adds latency to every page load. Consider a faster DNS provider.
Got: 314 ms
A128.2.42.10
AAAA—
CNAME—
NSNSAUTH3.NET.cmu.edu, NSAUTH2.NET.cmu.edu, NSAUTH1.NET.cmu.edu
MX
1 ASPMX.L.GOOGLE.COM
5 ALT2.ASPMX.L.GOOGLE.COM
5 ALT1.ASPMX.L.GOOGLE.COM
10 ALT4.ASPMX.L.GOOGLE.COM
10 ALT3.ASPMX.L.GOOGLE.COM
TXT
reftab-domain-verification=c24d073b23fed3af77c9e3b40010223f
[NRDR 36038_IN_TXT_cisco-ci-domain-verification=5f809f49f9d3ca48d84db537e031b200...
[NRDR 34503_IN_TXT_google-site-verification=JopPlnNv9VupQydpE3TiwZAEod-zouxEX0in...
[NRDR 32847_IN_TXT_facebook-domain-verification=vxpo0xkores42yfj9ggcdd2o2d2v2n 9...
facebook-domain-verification=vxpo0xkores42yfj9ggcdd2o2d2v2n
[NRDR 34068_IN_TXT_atlassian-domain-verification=H4RHVEsTq5YZaRen7VBly2a3AqWhfLM...
google-site-verification=m3lUupwhWqjbGCA6JswqWyBi7tkzh-BjbRiYuC6EXTg
[NRDR 31504_IN_TXT_v=spf1.include:_spf.cmu.edu.~all jxEj2x9CC1Gu8ePZldY84w]
00df4000000231leaa
google-site-verification=MYZf5OssFVvgYQF1snvJdiFbMjHy53WzLrnsVGkgpFU
[NRDR 34436_IN_TXT_google-site-verification=MYZf5OssFVvgYQF1snvJdiFbMjHy53WzLrns...
[NRDR 34190_IN_TXT_docusign=048da45a-23c6-4f6b-8f96-6dff4fa6b22b AWGRCMvgvpXmHSJ...
[NRDR 36124_IN_TXT_e2ma-verification=fu2 tn9dGsCpd6YZrmWG6O9dqw]
[NRDR 33014_IN_TXT_ZOOM_verify_FruZuJfdTeW1OOezpsuIVA +31oybl7gh2i74ky0SLQcg]
[NRDR 34438_IN_TXT_google-site-verification=pNbrq7j_EeIowr_Kw1Jfy46bmFWR9p1llXH_...
[NRDR 36125_IN_TXT_e2ma-verification=fu2 tn9dGsCpd6YZrmWG6O9dqw]
[NRDR 34437_IN_TXT_google-site-verification=m3lUupwhWqjbGCA6JswqWyBi7tkzh-BjbRiY...
MS=ms17583017
google-site-verification=O2gyijlOW-8BSOghh0tL_4N1PlWU_qznkYhUA22dLJ0
e2ma-verification=fu2
[NRDR 30017_IN_TXT_google-site-verification=O2gyijlOW-8BSOghh0tL_4N1PlWU_qznkYhU...
zoho-verification=zb38550127.zmverify.zoho.com
r4bgkix7EqRv+dJHKYelMrye44oR+366MsSA0lCP0TOcMK8wfs0bpTMDP1tLTZ66OFh0Qx+ZMLBCeVx0...
[NRDR 31057_IN_TXT_00df4000000231leaa QSq9rQj5GCBh30pVnLGMtQ]
google-site-verification=JopPlnNv9VupQydpE3TiwZAEod-zouxEX0inao6rggg
apple-domain-verification=yZrPHuazhdH42CPf
[NRDR 37073_IN_TXT_reftab-domain-verification=c24d073b23fed3af77c9e3b40010223f K...
google-site-verification=pNbrq7j_EeIowr_Kw1Jfy46bmFWR9p1llXH_leCdLrg
docusign=048da45a-23c6-4f6b-8f96-6dff4fa6b22b
atlassian-domain-verification=H4RHVEsTq5YZaRen7VBly2a3AqWhfLMxAL3wBScS8EB0Pg5x1v...
[NRDR 37284_IN_TXT_airtable-verification=878daeee4665d51015a6dda912bbb9f5 GCXTwR...
[NRDR 34415_IN_TXT_apple-domain-verification=yZrPHuazhdH42CPf dbWBQEISZeHDi/9KkK...
[NRDR 16337_IN_LOC_40.26.39.0.N.79.56.36.2.W.283.1.10.10 5PS/aNXhz6qcZ6tfoRdgeQ]
ZOOM_verify_FruZuJfdTeW1OOezpsuIVA
[NRDR 34441_IN_TXT_zoho-verification=zb38550127.zmverify.zoho.com sbctKhpo8bhwlN...
cisco-ci-domain-verification=5f809f49f9d3ca48d84db537e031b2007011ea11f6410de6a8a...
airtable-verification=878daeee4665d51015a6dda912bbb9f5
[NRDR 33356_IN_TXT_MS=ms17583017 io8/1MnXyp5PTqiijD8s0Q]
[NRDR 32936_IN_TXT_r4bgkix7EqRv+dJHKYelMrye44oR+366MsSA0lCP0TOcMK8wfs0bpTMDP1tLT...
SPF v=spf1 include:_spf.cmu.edu ~all
CAALookup not available with standard resolver
Resolved in 314 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+
Crawlability
robots.txt present, sitemap with 87 URLs
PASS
robots.txt present, sitemap with 87 URLs
Info::
robots.txt is present
Got: 110 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 87 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 110 B Sitemaps referenced 0 User-agents * Blocking No — crawling allowed
User-agent: *
Disallow: /cmufront/
Disallow: /myandrew
Disallow: /homepage/health/2009/fall/nobel-prize.shtml
sitemap.xml 200 OK
Type URL Set URLs 87 entries Valid XML Yes
Sample URLs:
A+
Domain Intelligence
cmu.edu — 41 years, 7 months old, hosted on CMU-ROUTER - Carnegie Mellon University, US
PASS
cmu.edu — 41 years, 7 months old, hosted on CMU-ROUTER - Carnegie Mellon University, US
Info::
Domain registered until Jul 31, 2027 (1 years, 3 months remaining)
Info::
Hosting: CMU-ROUTER - Carnegie Mellon University, US
Got: AS9
Domain expiry

410 days

July 31, 2027

SSL certificate

272 days

Issued by Internet2

Domain age

41 years, 7 months

Registered April 24, 1985

DNSSEC

Status unknown

Protects against DNS spoofing

Hosting

CMU-ROUTER - Carnegie Mellon University, US

ASN AS9

128.2.42.10

Registrar

Registrar unknown

Lock status unknown 3 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Registrar
Created April 24, 1985 (41 years, 7 months ago)
Expires July 31, 2027 (1 years, 3 months)
Last Updated January 30, 2026
Name Servers nsauth3.net.cmu.edu, nsauth1.net.cmu.edu, nsauth2.net.cmu.edu
Registrant Carnegie Mellon University
Hosting
IP Address 128.2.42.10
ASN AS9 (CMU-ROUTER - Carnegie Mellon University, US)
Provider CMU-ROUTER - Carnegie Mellon University, US
Data source: whois (0.9s)
A
HTTP Probe Timing
Total 528 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
111 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
103 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
209 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
528 ms
Total Time Total request time from DNS lookup through full response.
528 ms

Connection waterfall

DNS Lookup 111 ms TCP Connect 103 ms TLS Handshake 209 ms Server Processing 104 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.

Send Feedback