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https://bt.cn

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
88
GRADE
B
FIX
2
REVIEW
1
PASS
6
INFO
0
Probed from Madrid, Spain
302 Found
Checks
9
6 PASS 1 REVIEW 2 FIX
D
Redirect Chain
Action
2 redirect(s), 2391 ms total
FIX
2 redirect(s), 2391 ms total
Warning::
2 redirects before reaching final URL
Each redirect adds latency. Try to minimize the chain to 1 hop.
Info::
WWW normalization redirect
Info::
Uses 302 (temporary) redirect
If permanent, use 301 instead.
Got: https://bt.cn
Warning::
Redirect overhead: 2391 ms total
Got: 2391 ms

https://bt.cn

805 ms · HTTP/1.1

302

https://www.bt.cn/

638 ms · HTTP/1.1

302

https://www.bt.cn/new/index.html

948 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://bt.cn302805 msHTTP/1.1openresty
2https://www.bt.cn/302638 msHTTP/1.1openresty
3https://www.bt.cn/new/index.html200948 msHTTP/1.1openresty

See the visual redirect chain in the HTTP Probe tab →

Each redirect adds latency. Try to minimize the chain to 1 hop.

Why this matters

Redirect chain — each hop adds latency; combine into one redirect where possible.

Source: Google Search Central / web.dev

If permanent, use 301 instead.

Why this matters

302 (Found) is for genuinely temporary redirects — if this redirect is permanent, switch to 301 to preserve SEO equity.

Learn more ▾

Search engines treat 302 as temporary, keeping the original URL indexed and not transferring full link equity to the destination. Use 301 (Moved Permanently) for permanent redirects (HTTP→HTTPS, www-vs-non-www, URL restructures).

Source: Google Search Central

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
TLS Certificate Expiry & Recommendations
117 days until leaf cert expires — 3 issues to address
REVIEW

Certificate validity

117
days left
0d 30d 60d 90d+

Recommended actions

  • Submit your domain to hstspreload.org to be added to the Chrome preload list
  • 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, 40 ms lookup
PASS
1 A records, 40 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 157.255.129.251
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
Info::
Has 1 IPv6 (AAAA) record(s)
Got: 2001:19f0:7001:54fc:5400:2ff:fe9b:97f9
Info::
2 nameserver(s) configured
Got: vip4.alidns.com, vip3.alidns.com
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: 40 ms
Got: 40 ms
A157.255.129.251
AAAA2001:19f0:7001:54fc:5400:2ff:fe9b:97f9
CNAME—
NSvip4.alidns.com, vip3.alidns.com
MX
10 mail.bt.cn
TXT
SPF v=spf1 a mx -all
202006140135465jku4f66s84knkzqfhymyot20dlksu51gbge4j93nmd9rutp4i
google-site-verification=T_Dp27KV30n1mzB0BwaVHZzAR7CYJ7E6DCNU30fz1CY
CAALookup not available with standard resolver
Resolved in 40 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.

A+
IPv6 Readiness
IPv6 reachable (258 ms)
PASS
IPv6 reachable (258 ms)
Info::
IPv6 is configured and reachable at 2001:19f0:7001:54fc:5400:2ff:fe9b:97f9
Got: 258 ms connect
IPv6 Ready
AAAA Records 2001:19f0:7001:54fc:5400:2ff:fe9b:97f9 Connection Reachable (258 ms)
A+
Crawlability
robots.txt present, sitemap with 120 URLs
PASS
robots.txt present, sitemap with 120 URLs
Info::
robots.txt is present
Got: 59 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 120 entries
Info::
Sitemap index with 120 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 59 B Sitemaps referenced 0 User-agents * Blocking No — crawling allowed
User-agent: *
Allow: /
Disallow: /bbs/uc_server/avatar.php
sitemap.xml 200 OK
Type Sitemap Index URLs 120 entries Valid XML Yes
Child Sitemaps:
A
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
PASS
www/non-www, trailing slash, HTTP→HTTPS
Info::
www/non-www redirect configured correctly (preferred: non-www)
Warning::
HTTP→HTTPS redirect uses 302 instead of 301
Got: 302 temporary redirect Expected: 301 permanent redirect

www / non-www

302https://www.bt.cn/
200https://bt.cn/

Preferred variant: non-www

HTTP → HTTPS

302http://bt.cn/ → https://www.bt.cn/

Use 301 (permanent) instead of 302 (temporary)

A+
Domain Intelligence
bt.cn — via 厦门易名科技股份有限公司, 12 years, 5 months old
PASS
bt.cn — via 厦门易名科技股份有限公司, 12 years, 5 months old
Info::
Domain registered until Jan 22, 2036 (9 years, 10 months remaining)
Info::
Registrar: 厦门易名科技股份有限公司
Info::
Registrar lock is enabled
Domain cannot be transferred without explicit unlock from the registrar. This protects against unauthorized transfers.
Domain expiry

3508 days

January 22, 2036

SSL certificate

117 days

Issued by sslTrus

Domain age

12 years, 5 months

Registered January 22, 2014

DNSSEC

Status unknown

Protects against DNS spoofing

Hosting

Unknown

2001:19f0:7001:54fc:5400:2ff:fe9b:97f9

Registrar

厦门易名科技股份有限公司

Locked 2 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Registrar 厦门易名科技股份有限公司
Created January 22, 2014 (12 years, 5 months ago)
Expires January 22, 2036 (9 years, 10 months)
Name Servers vip3.alidns.com, vip4.alidns.com
Hosting
IP Address 2001:19f0:7001:54fc:5400:2ff:fe9b:97f9
Data source: whois (0.9s)

Domain cannot be transferred without explicit unlock from the registrar. This protects against unauthorized transfers.

Why this matters

Registrar lock (clientTransferProhibited et al.) prevents unauthorized domain transfers — strongest defense against domain hijacking.

Source: ICANN / domain-security best practice

A
HTTP Probe Timing
Total 705 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
168 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
174 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
179 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
705 ms
Total Time Total request time from DNS lookup through full response.
705 ms

Connection waterfall

DNS Lookup 168 ms TCP Connect 174 ms TLS Handshake 179 ms Server Processing 185 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.

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