Infrastructure
· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.DCDN & DeliveryActionNo CDN detectedFIX
Consider using a CDN to improve global delivery speed and reduce origin load.
BRedirect Chain1 redirect(s), 1618 ms totalREVIEW
https://zhihu.com
1254 ms · HTTP/1.1
https://www.zhihu.com/
364 ms · HTTP/1.1 FINAL
| # | URL | Status | Time | Protocol | Server |
|---|---|---|---|---|---|
| 1 | https://zhihu.com | 301 | 1254 ms | HTTP/1.1 | nginx/1.28.0 |
| 2 | https://www.zhihu.com/ | 403 | 364 ms | HTTP/1.1 | BLB/25.11.0.2 |
See the visual redirect chain in the HTTP Probe tab →
CIPv6 ReadinessActionNo IPv6 supportREVIEW
IPv6 support is increasingly important for global accessibility. About 40% of internet users have IPv6 connectivity.
No AAAA records — same impact as 'no IPv6 (AAAA) records'; IPv6-preferring clients pay extra latency falling back to IPv4.
Source: Google IPv6 stats
BCrawlabilityno robots.txt, no sitemapREVIEW
robots.txt is optional but recommended. It tells search engine crawlers which pages to index.
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.
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
No robots.txt found
This is fine for most sites — a missing robots.txt allows all crawling by default.
No sitemap found
Adding a sitemap helps search engines discover your pages.
BHTTP Probe TimingTotal 1271 ms — DNS, TCP, TLS, TTFB, content transfer breakdownREVIEW
Connection waterfall
BTLS Certificate Expiry & Recommendations238 days until leaf cert expires — 4 issues to addressREVIEW
Certificate validity
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 Records1 A records, 35 ms lookupPASS
| A | 43.135.83.2 |
| AAAA | — |
| CNAME | — |
| NS | ns3.dnsv5.com, ns4.dnsv5.com |
| MX | 5 mxbiz1.qq.com 10 mxbiz2.qq.com |
| TXT | apple-domain-verification=0ABf57rqECBcCKb6 google-site-verification=WreyhhjBpv_EcWw27fGRsO7yz4sy_6oiT1HeoJfv1JQ SPF v=spf1 include:spf.mail.qq.com -all 3nsr8c3w7yg4bngn0z53wr22hm54s5q2 m5g7qjk31l5d1hkq6m3zvcf6lg2f0h16 |
| CAA | Lookup not available with standard resolver |
Multiple A records provide failover if one server goes down.
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.
Informational: CAA (Certification Authority Authorization) records weren't checked in this scan.
A+URL Variantswww/non-www, trailing slash, HTTP→HTTPSPASS
www / non-www
HTTP → HTTPS
Consistent
A+Domain Intelligencezhihu.com — via DNSPod, Inc., 19 years, 1 months old, hosted on Tencent CloudPASS
1175 days
September 29, 2029
238 days
Issued by DigiCert, Inc.
19 years, 1 months
Registered June 15, 2007
Not enabled
Protects against DNS spoofing
Tencent Cloud
ASN AS132203
43.135.83.2
DNSPod, Inc.
Expiry timeline
Recommended actions
- Enable DNSSEC to protect visitors from DNS spoofing
- Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
DNSSEC protects against DNS spoofing attacks. While not required, enabling DNSSEC adds an additional layer of security. Contact your DNS provider to enable it.
Without DNSSEC, an attacker who can poison your DNS can hijack your domain — and SSL certs alone don't stop them.
Learn more ▾ ▴
DNSSEC adds cryptographic signatures to DNS records, preventing forged responses from poisoning resolver caches. Without it, an attacker who controls the network path can redirect your domain to a malicious server before any HTTPS handshake happens. Most modern registrars (Cloudflare, Google Domains, Route 53) enable it with one toggle.
Source: ICANN / RFC 4033
The domain can be transferred without an unlock step. Enable registrar lock (clientTransferProhibited) in your registrar's control panel to protect against unauthorized or accidental transfers.
Without registrar lock, an attacker who phishes your registrar credentials can transfer the domain in minutes — total brand hijack.
Learn more ▾ ▴
Registrar lock (clientTransferProhibited, clientUpdateProhibited, clientDeleteProhibited) requires extra verification before any transfer/update/delete. Every major registrar offers it free. Combined with 2FA on your registrar account, it's the strongest defense against domain hijacking.
Source: ICANN / domain-security best practice