HOW.IS
?

How is ctdns.cn?

Be careful risk 30/100

No valid HTTPS certificate, the site did not answer (OSError).

Why

02050100
finecarefulhigh risk
  • +10The registry did not report a usable creation date.
  • +20No valid HTTPS certificate.

Rule-based: domain age, blocklists, TLS. A heuristic, not a guarantee.

Site
down
OSError
HTTPS
invalid
Could not resolve host (ENODATA)
Age
?
creation date not reported
Blocklists
0
listings across 2 lists

Everything we looked at

DNS records1 record types
NSns4.ctdns.cn
ns2.ctdns.cn
ns3.ctdns.cn
ns1.ctdns.cn
Registration阿里云计算有限公司（万网）
registrar阿里云计算有限公司（万网）
nameserversns4.ctdns.cn ns1.ctdns.cn ns2.ctdns.cn ns3.ctdns.cn
statusok
HTTPS certificatenot valid
validno
problemCould not resolve host (ENODATA)
DNSSECinsecure

Domain is not signed with DNSSEC

. → cn → ctdns.cn
Email authenticationpoor
SPFnone
DMARCnone
DKIMnone of 1 common selectors

Whether mail claiming to be from this domain can be checked as genuine.

Security scoregrade D · 95/190
Basic Security
10/40missing: DNSSEC Enabled, Nameserver Diversity
Record Security
0/45missing: CAA Records, SPF Record, DMARC Record, DKIM Presence
Advanced Security
5/25missing: Mail Server Configuration, SOA Record Configuration, IPv6 Support
Domain Reputation
35/35
Threat Detection
45/45missing: Domain Age Check
Blocklists0 listings · 2 lookups
SURBL MultidomainURIBL Multidomain

Green: clean. Red: listed. Grey: the list did not answer.

Ask it yourself

Agents get this as data. Bought through the API, the checks behind this page cost $0.070: profile $0.025 + trust $0.020 + screenshot $0.020 + site status $0.005.

curl "https://how.is/v1/domain/trust?domain=ctdns.cn" \ -H "Authorization: Bearer $HOWIS_KEY" # or pay per call in USDC (x402), no key: the 402 tells your agent the price curl -i "https://how.is/v1/domain/profile?domain=ctdns.cn"

MCP: add https://how.is/mcp to Claude, Codex or Cursor (one-line install) and ask for domain_trust on ctdns.cn. Reference: /llms.txt.

IPv6. IPv6 readiness grade for ctdns.cn Does ctdns.cn work over IPv6? See the live check on aaaa.bot — website, mail and nameservers, graded A–F.

Watch ctdns.cn. DNS read at the source every 5 minutes; certificate, blocklists and expiry every 6 hours. You get an email only when something changes.

Watch — $1 / 30 days