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https://keio.ac.jp

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
6
INFO
1
Probed from Madrid, Spain
301 Moved Permanently
Checks
9
6 PASS 2 REVIEW
B
Crawlability
no robots.txt, no sitemap
REVIEW
no robots.txt, no sitemap
Info::
No robots.txt found
robots.txt is optional but recommended. It tells search engine crawlers which pages to index.
Info::
No sitemap.xml found
A sitemap helps search engines discover and index your pages more efficiently.

robots.txt is optional but recommended. It tells search engine crawlers which pages to index.

Why this matters

No robots.txt — crawlers fetch /robots.txt and get 404; not breaking but means default crawl behavior with no directives or sitemap reference.

Learn more ▾

A minimal robots.txt with `User-agent: * / Allow: / / Sitemap: https://example.com/sitemap.xml` covers the basics. Without it, crawlers behave fine but lose the sitemap signal and can't be selectively blocked from crawl-traps.

Source: robotstxt.org

A sitemap helps search engines discover and index your pages more efficiently.

Why this matters

No sitemap.xml — Google relies on crawl-graph discovery alone, slowing indexing of deep or fresh URLs.

Learn more ▾

A sitemap accelerates Google's discovery of new and updated content. Most CMSes auto-generate one; static-site frameworks need a build-step plugin. Reference it from robots.txt and submit in Search Console to confirm Google can fetch it.

Source: sitemaps.org / Google Search Central

robots.txt No robots.txt found

No robots.txt found

This is fine for most sites — a missing robots.txt allows all crawling by default.

sitemap.xml No sitemap found

No sitemap found

Adding a sitemap helps search engines discover your pages.

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

Certificate validity

167
days left
0d 30d 60d 90d+

Recommended actions

  • 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
4 A records, 44 ms lookup
PASS
4 A records, 44 ms lookup
Info::
Resolves to 4 IPv4 address(es)
Got: 13.224.83.10, 13.224.83.99, 13.224.83.46, 13.224.83.78
Info::
Has 8 IPv6 (AAAA) record(s)
Got: 2600:9000:2131:cc00:9:dcf4:5ec0:93a1, 2600:9000:2131:3800:9:dcf4:5ec0:93a1, 2600:9000:2131:3400:9:dcf4:5ec0:93a1, 2600:9000:2131:2800:9:dcf4:5ec0:93a1, 2600:9000:2131:e600:9:dcf4:5ec0:93a1, 2600:9000:2131:1200:9:dcf4:5ec0:93a1, 2600:9000:2131:1a00:9:dcf4:5ec0:93a1, 2600:9000:2131:f000:9:dcf4:5ec0:93a1
Warning::
CNAME record at zone apex
A CNAME at the zone apex can break MX and NS records. Use ALIAS/ANAME or A records instead.
Got: dh9uikqsvnji3.cloudfront.net
Info::
4 nameserver(s) configured
Got: ns-173.awsdns-21.com, ns-1482.awsdns-57.org, ns-687.awsdns-21.net, ns-1787.awsdns-31.co.uk
Info::
No MX records — email not configured via DNS
Info::
CAA records not checked
CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.
Info::
No SPF record found in TXT records
SPF helps prevent email spoofing. Add a TXT record starting with 'v=spf1'.
Info::
DNS resolution time: 44 ms
Got: 44 ms
A13.224.83.10, 13.224.83.99, 13.224.83.46, 13.224.83.78
AAAA2600:9000:2131:cc00:9:dcf4:5ec0:93a1, 2600:9000:2131:3800:9:dcf4:5ec0:93a1, 2600:9000:2131:3400:9:dcf4:5ec0:93a1, 2600:9000:2131:2800:9:dcf4:5ec0:93a1, 2600:9000:2131:e600:9:dcf4:5ec0:93a1, 2600:9000:2131:1200:9:dcf4:5ec0:93a1, 2600:9000:2131:1a00:9:dcf4:5ec0:93a1, 2600:9000:2131:f000:9:dcf4:5ec0:93a1
CNAMEdh9uikqsvnji3.cloudfront.net
NSns-173.awsdns-21.com, ns-1482.awsdns-57.org, ns-687.awsdns-21.net, ns-1787.awsdns-31.co.uk
MX—
TXT—
CAALookup not available with standard resolver
Resolved in 44 ms

A CNAME at the zone apex can break MX and NS records. Use ALIAS/ANAME or A records instead.

Why this matters

CNAME at the apex (example.com) breaks every other apex record (MX, TXT, NS) — DNS-protocol violation per RFC 1034.

Learn more ▾

RFC 1034 forbids CNAME alongside other records at the same name. Some DNS providers offer ALIAS / ANAME / flattened-CNAME records that work around this — use those instead. Otherwise apex-level CNAME breaks email (no MX), domain ownership verification (no TXT), and more.

Source: RFC 1034

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.

SPF helps prevent email spoofing. Add a TXT record starting with 'v=spf1'.

Why this matters

Without SPF, receiving servers can't validate sending IPs — your domain is easier to spoof in phishing.

Learn more ▾

SPF complements DMARC. Both should be published. SPF records list authorized sending IPs (e.g., `v=spf1 include:_spf.google.com ~all` for Google Workspace). After publishing, verify in Google Postmaster Tools or mxtoolbox.

Source: RFC 7208 (SPF)

A
Redirect Chain
1 redirect(s), 19 ms total
PASS
1 redirect(s), 19 ms total
Info::
Single redirect
Got: https://www.keio.ac.jp → https://www.keio.ac.jp/ja/ (301)

https://www.keio.ac.jp

9 ms · HTTP/1.1

301

https://www.keio.ac.jp/ja/

10 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://www.keio.ac.jp3019 msHTTP/1.1CloudFront
2https://www.keio.ac.jp/ja/20010 msHTTP/1.1CloudFront

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 2600:9000:2131:cc00:9:dcf4:5ec0:93a1, 2600:9000:2131:3800:9:dcf4:5ec0:93a1, 2600:9000:2131:3400:9:dcf4:5ec0:93a1, 2600:9000:2131:2800:9:dcf4:5ec0:93a1, 2600:9000:2131:e600:9:dcf4:5ec0:93a1, 2600:9000:2131:1200:9:dcf4:5ec0:93a1, 2600:9000:2131:1a00:9:dcf4:5ec0:93a1, 2600:9000:2131:f000:9:dcf4:5ec0:93a1
Got: 1 ms connect
IPv6 Ready
AAAA Records 2600:9000:2131:cc00:9:dcf4:5ec0:93a1, 2600:9000:2131:3800:9:dcf4:5ec0:93a1, 2600:9000:2131:3400:9:dcf4:5ec0:93a1, 2600:9000:2131:2800:9:dcf4:5ec0:93a1, 2600:9000:2131:e600:9:dcf4:5ec0:93a1, 2600:9000:2131:1200:9:dcf4:5ec0:93a1, 2600:9000:2131:1a00:9:dcf4:5ec0:93a1, 2600:9000:2131:f000:9:dcf4:5ec0:93a1 Connection Reachable (1 ms)
A+
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
PASS
www/non-www, trailing slash, HTTP→HTTPS
Info::
HTTP correctly 301-redirects to HTTPS

www / non-www

200https://www.keio.ac.jp/
https://keio.ac.jp/

HTTP → HTTPS

301http://www.keio.ac.jp/ → https://www.keio.ac.jp/

Consistent

A+
HTTP Probe Timing
Total 59 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
48 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
1 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
3 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
59 ms
Total Time Total request time from DNS lookup through full response.
59 ms

Connection waterfall

DNS Lookup 48 ms TCP Connect 1 ms TLS Handshake 3 ms Server Processing 7 ms Content Transfer 0 ms
A+
CDN & Delivery
AWS CloudFront (Hit from cloudfront)
PASS
AWS CloudFront (Hit from cloudfront)
Info::
Site is served via AWS CloudFront CDN (edge: MAD53-P6)
Got: x-amz-cf-id: P_SQIdDqefYUHkZEpvibcLaqZNMH1EdsEdk136G22bd3_WkjjHDGmQ==
Info::
CDN cache status: Hit from cloudfront
CDN Detected: AWS CloudFront
Provider AWS CloudFront Cache Status Hit from cloudfront Evidence x-amz-cf-id: P_SQIdDqefYUHkZEpvibcLaqZNMH1EdsEdk136G22bd3_WkjjHDGmQ==
Domain Intelligence
Domain intelligence data not available
INFO
Domain intelligence data not available

RDAP and WHOIS lookup both failed

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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