Infrastructure

· 17 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

Probed from Singapore, Singapore

200 OK

Checks

5 PASS 10 REVIEW 1 FIX

CDN & Delivery

Action

No CDN detected

FIX

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 (document or assets)

Consider using a CDN to improve global delivery speed and reduce origin load.

DNS Records

Action

1 A records, 235 ms lookup

REVIEW

1 A records, 235 ms lookup

Resolves to 1 IPv4 address(es)

Got: 202.194.15.159

Single A record — no DNS redundancy

Multiple A records provide failover if one server goes down.

Has 1 IPv6 (AAAA) record(s)

Got: 2001:da8:7000:15:202:194:15:159

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: econ.sdu.edu.cn

No NS records found

No MX records — email not configured via DNS

No SPF record found in TXT records

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

DNS resolution is slow (235 ms)

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

Got: 235 ms

A	202.194.15.159
AAAA	2001:da8:7000:15:202:194:15:159
CNAME	econ.sdu.edu.cn
NS	—
MX	—
TXT	—
CAA	Lookup not available with standard resolver

Resolved in 235 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

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

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)

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

DNSSEC

Unsigned (DNSSEC not deployed)

REVIEW

Unsigned (DNSSEC not deployed)

DNSSEC is not deployed

The zone is not DNSSEC-signed. Users on validating resolvers (Cloudflare 1.1.1.1, Quad9 9.9.9.9, growing default in mobile resolvers) get no protection against DNS spoofing for this domain. Most registrars now offer DNSSEC at a single click; consider enabling it for sites where authenticity matters (banking, healthcare, government).

CAA Records

No CAA records (any CA may issue certificates)

REVIEW

No CAA records (any CA may issue certificates)

No CAA records published

Without CAA records, any publicly-trusted CA can issue certificates for this domain. Adding a CAA record (`yourdomain. IN CAA 0 issue "letsencrypt.org"`) restricts issuance to CAs you authorize. Required by CAB Forum baseline since 2017; the default of 'any CA' is widely supported but is the broader attack surface for issuance fraud.

Reverse DNS

Action

0/2 IPs match cert SAN

REVIEW

0/2 IPs match cert SAN

PTR lookup failed for 202.194.15.159: lookup 202.194.15.159: no such host

No reverse DNS record set for this IP. Common on bare cloud-VM IPs without provider-side PTR; not a security issue.

PTR lookup failed for 2001:da8:7000:15:202:194:15:159: lookup 2001:da8:7000:15:202:194:15:159: no such host

No reverse DNS record set for this IP. Common on bare cloud-VM IPs without provider-side PTR; not a security issue.

Multi-Resolver DNS Speed

Action

Mean 190ms across 3 resolvers (spread 240ms)

REVIEW

Mean 190ms across 3 resolvers (spread 240ms)

Google: 79ms

Got: 79ms via 8.8.8.8:53

Cloudflare: 174ms

Got: 174ms via 1.1.1.1:53

Quad9: 319ms

Got: 319ms via 9.9.9.9:53

High latency spread between resolvers: 240ms (min 79ms / max 319ms)

Wide gap between the fastest and slowest public resolver suggests a geographic anycast issue or an authoritative-server cache problem. Users in different regions will see materially different DNS times.

Crawlability

no robots.txt, no sitemap

REVIEW

no robots.txt, no sitemap

No robots.txt found

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

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.

TLS Certificate Expiry & Recommendations

128 days until leaf cert expires — 4 issues to address

REVIEW

Certificate validity

128

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

CDN Cache Observability

No CDN cache-status headers in the response

REVIEW

No CDN cache-status headers in the response

Without an X-Cache / CF-Cache-Status / X-Vercel-Cache / Age header, you can't tell from outside whether a request hit the cache or went to origin. Operationally important: enables debugging stale-content reports and verifying cache rules. Most managed CDN platforms emit at least one of these by default; absence often means the platform's diagnostic headers are stripped at an upstream proxy.

Operational Status Page

No status page link detected

REVIEW

No status page link detected

No operational status page link detected

Status pages communicate planned maintenance and incidents to users -- a hallmark of operationally-mature services. Most SaaS teams publish one via Atlassian Statuspage, Instatus, BetterUptime, or a self-hosted Cachet. Smaller sites legitimately don't need one; flagged as Info, not a failure.

Health Check Endpoint

No conventional health endpoint found

REVIEW

No conventional health endpoint found

Health endpoints (/health, /healthz, /status, /ping, /api/health) let uptime monitors, load balancers, and orchestration systems (Kubernetes, ECS, Fly.io) verify the service is alive. Marketing sites and small services often skip them legitimately; flagged as Info, not a failure. Probe results: /api/health: 404, /health: 404, /healthz: 404, /ping: 404, /status: 404.

A+

Subdomain Takeover

No subdomain takeover risk detected

PASS

No subdomain takeover risk detected

CNAME does not point at a known takeover-able service

A+

Redirect Chain

No redirects — direct access

PASS

No redirects — direct access

Got: https://www.econ.sdu.edu.cn

https://www.econ.sdu.edu.cn

483 ms · HTTP/1.1 FINAL

#	URL	Status	Time	Protocol	Server
1	https://www.econ.sdu.edu.cn	200	483 ms	HTTP/1.1	*********

A+

IPv6 Readiness

IPv6 reachable (78 ms)

PASS

IPv6 reachable (78 ms)

IPv6 is configured and reachable at 2001:da8:7000:15:202:194:15:159

Got: 78 ms connect

IPv6 Ready

AAAA Records 2001:da8:7000:15:202:194:15:159 Connection Reachable (78 ms)

URL Variants

www/non-www, trailing slash, HTTP→HTTPS

PASS

www/non-www, trailing slash, HTTP→HTTPS

HTTP→HTTPS redirect is not permanent

Got: HTTP 302 Expected: 301 or 308 permanent redirect

www / non-www

200https://www.econ.sdu.edu.cn/

403https://econ.sdu.edu.cn/

HTTP → HTTPS

302http://www.econ.sdu.edu.cn/ → https://www.econ.sdu.edu.cn/index.htm

Use a permanent redirect (301 or 308) instead of a temporary one

HTTP Probe Timing

Total 614 ms — DNS, TCP, TLS, TTFB, content transfer breakdown

PASS

DNS Lookup

221 ms

TCP Connect

74 ms

TLS Handshake

149 ms

Time to First Byte

528 ms

Total Time

614 ms

Connection waterfall

DNS Lookup 221 ms TCP Connect 74 ms TLS Handshake 149 ms Server Processing 84 ms Content Transfer 86 ms

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.