Skip to main content
DNS Tool
Engineer's DNS Intelligence Report
Generated 17 Aug 2026, 20:39 UTC
Duration 63.4s
Version v26.51.0-108-gf8e4afc1c
Integrity edb9508953b273d8d55ff47f2351bcc0d7f506f0a70535b71328a14ff7a4c0aae9f5c17513121420198a2a259c5e67d5029ce4710a81ac643a1113c78a2643da
Subject Domain
cloudflare.com

Engineer's DNS Intelligence Report

cloudflare.com Low Risk
17 Aug 2026, 20:39 UTC · 63.4s ·v26.51.0-108-gf8e4afc1c · SHA-3-512: edb9✱✱✱✱ Verify ·Archived ·Cross-Referenced
Executive Topology Replay
Recon Mode Snapshot Re-analyze New Domain
Engineer workspace · evidence preserved

Read the verdict first. Descend only as far as the incident requires.

This report keeps the complete technical record while separating decision, interpretation, evidence, and raw reproduction into a stable disclosure gradient.

L0PostureL1InterpretationL2EvidenceL3Raw & reproduce
Hurry path
MX & Routing Subdomains DNSSEC What changed
KEYBOARD !1@2#3$4%5^6 jump to that section · esc back to the verdict
Golden-fixture baseline domain. This domain is part of the golden-fixture corpus: its recorded scan snapshot is the tool's regression baseline. A scan of it reproducing the snapshot is the baseline returning its own value — expected agreement, not independent validation.
DNS Security & Trust Posture
Confidence: MODERATE · 64/100
7 protocols configured, 2 not configured Why we go beyond letter grades
Jump To: MTA-STS TLS-RPT
Sorted by severity — worst first
Email Spoofing
Protected
Brand Impersonation
Protected
DNS Tampering
Protected
Certificate Control
Configured
Monitoring
Partial
DANE
Unconfirmed
TRACE L0 · Monitoring — Partial L1 · 01 · Email Security · DMARC rua / TLS-RPT L3 · Reproduce commands
Not Configured
MTA-STS, TLS-RPT
Configured
SPF (hard fail), DMARC (reject), DKIM, BIMI, DANE, DNSSEC, CAA
Priority Actions Achievable posture: Hardened
Low Add TLS-RPT Reporting

Your domain has DNSSEC + DANE — the strongest email transport security available. TLS-RPT (TLS Reporting) sends you reports about TLS connection failures when other servers try to deliver mail to your domain.

RFC 8460
Low Deploy MTA-STS

MTA-STS enforces TLS encryption for inbound mail delivery, preventing downgrade attacks on your mail transport.

RFC 8461
Open Remediation Workspace — Copy-Paste Ready Records
Registrar (RDAP) OBSERVED LIVE
Cloudflare, Inc.
Where domain was purchased
Email Service Provider
Unknown
Strongly Protected
Web Hosting
Unknown
Where website is hosted
DNS Hosting
Cloudflare Enterprise
Where DNS records are edited
Footprint Cloudflare 10 SaaS Services
01 Identity & policy · L1 Email Security Can this domain be impersonated by email? SPF DMARC DKIM MTA-STS TLS-RPT MX & Routing Protected
Email Security Methodology Can this domain be impersonated by email? No SPF and DMARC reject policy enforced

SPF Record RFC 7208 §4 Gold

Does this domain declare who may send email on its behalf? Yes
Success -all 6/10 lookups

SPF valid with strict enforcement (-all), 6/10 lookups

v=spf1 ip4:199.15.212.0/22 ip4:173.245.48.0/20 include:_spf.google.com include:spf1.mcsv.net include:spf.mandrillapp.com include:mail.zendesk.com include:stspg-customer.com include:_spf.salesforce.com -all
RFC 7489: -all may cause rejection before DMARC evaluation, preventing DKIM from being checked
RFC 7208 Conformant — This SPF record conforms to the syntax and semantics defined in RFC 7208 §4.
RFC Failure Mode: Unlike DMARC (where unknown tags are silently ignored per RFC 7489 §6.3), SPF with unrecognized mechanisms produces a PermError per RFC 7208 §4.6 — the record fails loudly rather than silently.
Related CVEs: CVE-2024-7208 (multi-tenant domain spoofing), CVE-2024-7209 (shared SPF exploitation), CVE-2023-51764 (SMTP smuggling bypasses SPF)
SPF hard fail (-all): compliance-strong, but can short-circuit DMARC. RFC 7489 notes that -all can cause some receivers to reject mail during the SMTP transaction — before DKIM is checked and before DMARC can evaluate the result. A message that would pass DMARC via DKIM alignment may be rejected prematurely. For most domains, ~all + DMARC p=reject is the strongest compatible posture — it allows every authentication method (SPF, DKIM, DMARC) to be fully evaluated before a decision is made.
DMARC is set to reject — enforcement is strong. However, some receivers may still reject messages on SPF hard fail before DKIM alignment is checked. Switching to ~all + p=reject would provide the same enforcement with full DMARC compatibility.

DMARC Policy RFC 7489 §6.3 Gold

Are spoofed emails rejected or quarantined? Yes — reject policy
Success p=reject

DMARC policy reject (100%) - excellent protection

v=DMARC1; p=reject; sp=reject; adkim=r; aspf=r; pct=100; rua=mailto:a1c47f179bc04efd8ee4dcd4d85dfc65@dmarc-reports.cloudflare.net,mailto:rua@cloudflare.com
Alignment: SPF relaxed DKIM relaxed sp=reject
No forensic reporting (ruf) tag — this is correct. The absence of ruf= is not a gap. RFC 7489 §7.3 warns that forensic reports can expose PII (full message headers or bodies). Google, Microsoft, and Yahoo do not honour ruf= requests regardless. The DMARCbis draft (draft-ietf-dmarc-dmarcbis) has formally removed ruf= from the specification, confirming its deprecation. Omitting ruf= is the recommended modern practice. RFC 7489 §7.3 — Forensic Reports
Reported to Cloudflare DMARC (Cloudflare)
RFC 7489 Conformant — DMARC record conforms to RFC 7489 §6.3 with full enforcement.
DMARCbis (Pending): draft-ietf-dmarc-dmarcbis will elevate DMARC to Standards Track, obsolete RFC 7489, replace pct= with t= (testing flag), add np= (non-existent subdomain policy), and mandate DNS tree walk for policy discovery instead of the Public Suffix List.
Related CVEs: CVE-2024-49040 (Exchange sender spoofing), CVE-2024-7208 (multi-tenant DMARC bypass)

DKIM Records RFC 6376 §3.6 Gold

Are outbound emails cryptographically signed? Not discoverable
Weak Keys 2048-bit

Found 4 DKIM selector(s) with weak key(s) (below 2048-bit RSA)

SPF authorizes Google Workspace servers, but MX records point to self-hosted infrastructure. The Google Workspace SPF include likely supports ancillary services (e.g., calendar invitations, shared documents) rather than primary mailbox hosting.
1024-bit key (weak, upgrade to 2048)
1024-bit key (weak, upgrade to 2048)
1024-bit key (weak, upgrade to 2048)
k1._domainkey 1024-bit Weak
k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDbNrX2cY/GUKIFx2G/1I00ftdAj713WP9AQ1xir85i89sA2guU0ta4UX1Xzm06XIU6iBP41VwmPwBGRNofhBVR+e6WHUoNyIR4Bn84LVcfZE20rmDeXQblIupNWBqLXM1Q+VieI/eZu/7k9/vOkLSaQQdml4Cv8lb3PcnluMVIhQIDAQAB;
mandrill._domainkey MailChimp (Mandrill) 1024-bit Weak
v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCrLHiExVd55zd/IQ/J/mRwSRMAocV/hMB3jXwaHH36d9NaVynQFYV8NaWi69c1veUtRzGt7yAioXqLj7Z4TeEUoOLgrKsn8YnckGs9i3B3tVFB+Ch/4mPhXWiNfNdynHWBcPcbJ8kjEQ2U8y78dHZj1YeRXXVvWob2OaKynO8/lQIDAQAB
s1._domainkey 2048-bit Adequate
k=rsa; t=s; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA1m74n5R+xcz+ICbNBWRIlQeHI65Hjp67+P59XSe71jItafrcJ4/5y/UvU+uNg7KNeOcEsotGo7QvLN87hqZSZqfzVyyGnQuEUXoKPdKokD6Pa5KmJSqbA5Y/f977HpikU9Xtd7Orc7ctRLK6H5QFvGwRi+oC9NRkgNB55UUnLbbkKK+LGeTw4Ghmr5gupw7iYzFXZ1qlFNqV6s9Pmgb+b7oDv+OfQxB/MJyUzQ5eWdKlJWfmW3s77J3fHFfysUbKKUBxEXPxNiMFRG1ClllZ4+AYRh1jrFpjbvZ5j43kqahKXeHDNkF+Gpptd7ufWIevAPTQDSVdKB9vyJQN6wfcQQIDAQAB
smtpapi._domainkey SendGrid 1024-bit Weak
k=rsa; t=s; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDPtW5iwpXVPiH5FzJ7Nrl8USzuY9zqqzjE0D1r04xDN6qwziDnmgcFNNfMewVKN2D1O+2J9N14hRprzByFwfQW76yojh54Xu3uSbQ3JP0A7k8o8GutRF8zbFUA8n0ZH2y0cIEjMliXY4W4LwPA7m4q0ObmvSjhd63O9d8z1XkUBwIDAQAB
RFC Stance: RFC 6376 (Internet Standard) defines the DKIM mechanism. DKIM selectors are not publicly enumerable — absence in a scan does not prove absence of signing.
Known Vulnerabilities: DKIM l= tag body length vulnerability (attacker appends unsigned content to signed mail), weak key exploitation (keys below 1024-bit are cryptographically breakable per RFC 6376 §3.3.3), DKIM replay attacks (re-sending legitimately signed messages at scale)

MTA-STS RFC 8461 §3 Gold

Can attackers downgrade SMTP to intercept mail? Not prevented
Warning

No MTA-STS record found

MTA-STS policy enforcement is evaluated in Mail Transport Security below.

TLS-RPT RFC 8460 §3 Gold

Will failures in TLS delivery be reported? No reporting
Warning

No TLS-RPT record found

Email Security Management Actively Managed

Intelligence: This domain uses dedicated email security management — indicating continuous monitoring and professional oversight, not a "set and forget" configuration. Reporting destinations reveal the operational security partner network, and we extract that intelligence directly from DNS.
Cloudflare DMARC by Cloudflare
DMARC
DMARC aggregate reports (rua)

DMARC External Reporting Authorization RFC 7489 §7.1

Are external report receivers authorized? Could not verify
Unverified

Could not verify 1 of 1 external reporting domains — DNS lookup did not complete

External Domain Authorization Auth Record
dmarc-reports.cloudflare.net Unverified —
Could not verify external reporting authorization for dmarc-reports.cloudflare.net — the DNS lookup for cloudflare.com._report._dmarc.dmarc-reports.cloudflare.net did not complete. Treated as unverified, not a finding; re-run to confirm.

Why "unverified": The authorization TXT record could not be resolved this scan (a transient DNS failure, not a confirmed absence). We do not report it as missing, because asserting absence from a failed lookup would be a false finding. Re-run the scan to confirm.

02 Chain of authority · L1 Domain Security Can DNS answers and certificate issuance be trusted? DANE / TLSA CAA Delegation DNSSEC Operations DNSSEC & NS Protected
DANE / TLSA Gold Recon Methodology Can mail servers establish identity without a public CA? Yes
RFC 7672 §3 RFC 6698 §2 4/4 MX

DANE configured — TLSA records found for all 4 MX hosts

MX Host Usage Selector Match Certificate Data
mxa-canary.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 a07b590f83a529f9fa4e7cc1c99c1553adce94f2c87766290175236d47601968
mxa-canary.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 8dcca72bfe3c99e76ada76b7b29e8e813428949a78ad2d61c33bceaf3de4b1f9
mxa-canary.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 96c2b0229b798135d733e41d6e5817c67e853dbb0a70b2cfe22f462a1d085751
mxa-canary.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 e2e4ff54d68bc2aa58f06d7b0841305c591c481d8ee622cbb3ecd245d83ae4a0
mxa-canary.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 7fed38b4b0b86d8a5834e5a1aeabbb34a5a04159a281d62ff42d6a7bde310f36
mxa-canary.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 10ba5e544c24746e0f7182959cda4463f136ee842adbc2f7293296ea5ae371e0
mxa-canary.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 8e4d63a1e1f68c7651bc9e0a6a4ac597c78a9dd5a0cc85dfcec01dd5586214fc
mxa-canary.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 e8a50fb03ed780a45bca47a36af2dca2bc13ad4be117b296285ed8754d7350cb
mxa-canary.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 9122be3be7bcc604fd296255f5783c3d945b4aab46418f87d029ebf74db191e1
mxa-canary.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 64f37496c62dd5352732c5805df3330f6c9d034b981aa615a0157d53b433f488
mxa-canary.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 66928f8426b14ef22919369c5a03a000d9e1ef01e78cc7899090ac80a9aa982d
mxa.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 10ba5e544c24746e0f7182959cda4463f136ee842adbc2f7293296ea5ae371e0
mxa.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 64f37496c62dd5352732c5805df3330f6c9d034b981aa615a0157d53b433f488
mxa.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 66928f8426b14ef22919369c5a03a000d9e1ef01e78cc7899090ac80a9aa982d
mxa.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 7fed38b4b0b86d8a5834e5a1aeabbb34a5a04159a281d62ff42d6a7bde310f36
mxa.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 8dcca72bfe3c99e76ada76b7b29e8e813428949a78ad2d61c33bceaf3de4b1f9
mxa.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 8e4d63a1e1f68c7651bc9e0a6a4ac597c78a9dd5a0cc85dfcec01dd5586214fc
mxa.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 9122be3be7bcc604fd296255f5783c3d945b4aab46418f87d029ebf74db191e1
mxa.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 96c2b0229b798135d733e41d6e5817c67e853dbb0a70b2cfe22f462a1d085751
mxa.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 a07b590f83a529f9fa4e7cc1c99c1553adce94f2c87766290175236d47601968
mxa.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 e2e4ff54d68bc2aa58f06d7b0841305c591c481d8ee622cbb3ecd245d83ae4a0
mxa.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 e8a50fb03ed780a45bca47a36af2dca2bc13ad4be117b296285ed8754d7350cb
mxb.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 10ba5e544c24746e0f7182959cda4463f136ee842adbc2f7293296ea5ae371e0
mxb.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 64f37496c62dd5352732c5805df3330f6c9d034b981aa615a0157d53b433f488
mxb.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 66928f8426b14ef22919369c5a03a000d9e1ef01e78cc7899090ac80a9aa982d
mxb.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 7fed38b4b0b86d8a5834e5a1aeabbb34a5a04159a281d62ff42d6a7bde310f36
mxb.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 8dcca72bfe3c99e76ada76b7b29e8e813428949a78ad2d61c33bceaf3de4b1f9
mxb.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 8e4d63a1e1f68c7651bc9e0a6a4ac597c78a9dd5a0cc85dfcec01dd5586214fc
mxb.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 9122be3be7bcc604fd296255f5783c3d945b4aab46418f87d029ebf74db191e1
mxb.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 96c2b0229b798135d733e41d6e5817c67e853dbb0a70b2cfe22f462a1d085751
mxb.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 a07b590f83a529f9fa4e7cc1c99c1553adce94f2c87766290175236d47601968
mxb.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 e2e4ff54d68bc2aa58f06d7b0841305c591c481d8ee622cbb3ecd245d83ae4a0
mxb.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 e8a50fb03ed780a45bca47a36af2dca2bc13ad4be117b296285ed8754d7350cb
mxb-canary.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 8dcca72bfe3c99e76ada76b7b29e8e813428949a78ad2d61c33bceaf3de4b1f9
mxb-canary.global.inbound.cf-emailsecurity.net 3 DANE-EE (Domain-issued certificate) Public key only (SubjectPublicKeyInfo) SHA-256 9122be3be7bcc604fd296255f5783c3d945b4aab46418f87d029ebf74db191e1
Email Transport Security

Two mechanisms protect email in transit. DANE is the primary standard; MTA-STS is the alternative for domains that cannot deploy DNSSEC:

  • DNSSEC + DANE (RFC 7672) — Cryptographic chain of trust from DNS root to mail server certificate. Eliminates reliance on certificate authorities. No trust-on-first-use weakness. Requires DNSSEC.
  • MTA-STS (RFC 8461) — HTTPS-based policy requiring TLS for mail delivery. Works without DNSSEC but relies on CA trust and is vulnerable on first use (§10). Created for domains where “deploying DNSSEC is undesirable or impractical” (§2).
This domain uses DNSSEC + DANE — the strongest cryptographic transport security. DANE binds TLS certificates to DNSSEC-signed DNS records, creating a verifiable chain of trust from root to mail server (RFC 7672 §1.3). MTA-STS could complement this for senders that don't validate DNSSEC, but DANE alone provides the highest level of protection available.

Industry trend: Microsoft Exchange Online enforces inbound DANE with DNSSEC (GA October 2024), and providers like Proton Mail and Fastmail also support DANE. Google Workspace does not support DANE and relies on MTA-STS. Both mechanisms coexist because DANE is backward-compatible — senders skip the check if the domain isn't DNSSEC-signed (RFC 7672 §1.3).

CAA RFC 8659 §4 Gold Success IODEF

Does this domain restrict who can issue TLS certificates? Yes

CAA configured - only Sectigo, DigiCert, Let's Encrypt, cansignhttpexchanges=yes, ssl.com can issue certificates (wildcard issuance: ssl.com, Sectigo, DigiCert, Let's Encrypt, cansignhttpexchanges=yes per RFC 8659 §4.3)

Authorized CAs: Sectigo DigiCert Let's Encrypt cansignhttpexchanges=yes ssl.com
0 iodef "mailto:tls-abuse@cloudflare.com"
0 issue "comodoca.com"
0 issue "digicert.com; cansignhttpexchanges=yes"
0 issue "letsencrypt.org"
0 issue "pki.goog; cansignhttpexchanges=yes"
0 issue "ssl.com"
0 issuewild "comodoca.com"
0 issuewild "digicert.com; cansignhttpexchanges=yes"
0 issuewild "letsencrypt.org"
0 issuewild "pki.goog; cansignhttpexchanges=yes"
0 issuewild "ssl.com"
Since September 2025, all public CAs must verify domain control from multiple geographic locations (Multi-Perspective Issuance Corroboration, CA/B Forum Ballot SC-067). CAA records are now checked from multiple network perspectives before certificate issuance.
Delegation Consistency 6 Issues

Delegation consistency: 6 issue(s) found — Parent/child NS delegation alignment: DS↔DNSKEY, glue records, TTL drift, SOA serial sync.

Findings:
  • In-bailiwick NS ns3.cloudflare.com has no glue records at parent — resolution may fail
  • In-bailiwick NS ns4.cloudflare.com has no glue records at parent — resolution may fail
  • In-bailiwick NS ns5.cloudflare.com has no glue records at parent — resolution may fail
  • In-bailiwick NS ns6.cloudflare.com has no glue records at parent — resolution may fail
  • In-bailiwick NS ns7.cloudflare.com has no glue records at parent — resolution may fail
  • Could not retrieve NS TTL from parent zone

DS ↔ DNSKEY Alignment Aligned

DS Key TagDS AlgorithmDNSKEY Key TagDNSKEY Algorithm
2371 13 2371 13

Glue Record Completeness Incomplete

NameserverIn-BailiwickIPv4 GlueIPv6 GlueStatus
ns3.cloudflare.com Missing
ns4.cloudflare.com Missing
ns5.cloudflare.com Missing
ns6.cloudflare.com Missing
ns7.cloudflare.com Missing

NS TTL Comparison Drift

Child TTL: 86400s Drift: 0s

SOA Serial Consistency Consistent

ns3.cloudflare.com: 2.412182421e+09
ns4.cloudflare.com: 2.412182421e+09
ns5.cloudflare.com: 2.412182421e+09
ns6.cloudflare.com: 2.412182421e+09
ns7.cloudflare.com: 2.412182421e+09
DNSSEC Operations Deep Dive 1 Issue

DNSSEC operational notes: 1 item(s) to review — KSK/ZSK differentiation, RRSIG expiry windows, NSEC/NSEC3 analysis, and rollover readiness.

Findings:
  • CDS/CDNSKEY automation present but only single KSK — pre-publish second KSK before rollover

DNSKEY Inventory 2 Keys

RoleKey TagAlgorithmKey Size
ZSK 34505 ECDSA P-256/SHA-256 256 bits
KSK 2371 ECDSA P-256/SHA-256 256 bits

RRSIG Signatures 0 Signatures

No RRSIG records found.

Denial of Existence NSEC

NSEC records expose zone contents via ordered names (zone walking). Consider NSEC3 for zone enumeration protection.

Rollover Readiness Partial

Multiple KSKs:
CDS Published:
CDNSKEY Published:
Automation: full
Domain Security Methodology Can DNS responses be tampered with in transit? No DNSSEC signed; a validating resolver confirmed the cryptographic chain of trust via the AD flag (RFC 4035 §3.2.3)

DNSSEC RFC 4033 §2 Gold Signed ECDSA P-256/SHA-256 Modern

DNSSEC fully configured and validated — AD (Authenticated Data) flag set by validating resolvers confirming cryptographic chain of trust from root to zone (RFC 4035 §3.2.3)

Algorithm Observation: ECDSA P-256/SHA-256 — MUST implement, recommended default (RFC 8624 §3.1)
All current DNSSEC algorithms use classical cryptography. Post-quantum DNSSEC standards are in active IETF development (draft-sheth-pqc-dnssec-strategy) but no PQC algorithms have been standardized for DNSSEC yet.
Chain of trust: Root → TLD → Domain. DNS responses are cryptographically authenticated and tamper-evident.
AD Flag: Validated - Resolver (Cloudflare) confirmed cryptographic signatures
DS Record (at registrar):
2371 13 2 32996839A6D808AFE3EB4A795A0E6A7A39A76FC52FF228B22B76F6D63826F2B9

NS Delegation Verified

5 nameserver(s) configured

Nameservers: ns3.cloudflare.com ns4.cloudflare.com ns5.cloudflare.com ns6.cloudflare.com ns7.cloudflare.com
Enterprise DNS (Dedicated Infrastructure)
All 5 nameservers are cloudflare.com-branded, indicating organization-operated DNS infrastructure. This is typical of large enterprises, government agencies, and organizations that maintain full control of their DNS resolution chain.
Multi-Resolver Verification Recon: Consensus reached - 5 resolvers (Cloudflare, Google, Quad9, OpenDNS, DNS4EU) agree on DNS records

HTTPS / SVCB Records RFC 9460 Success HTTPS HTTP/3

HTTPS records found, HTTP/3 supported

PriorityTargetALPNECHRaw
1 . h3, h2 No cloudflare.com. 300 IN HTTPS 1 . alpn="h3,h2" ipv4hint="104.16.132.229,104.16.133.229" ipv6hint="2606:4700::6810:84e5,2606:4700::6810:85e5"

CDS / CDNSKEY (DNSSEC Automation) RFC 7344 Success CDS CDNSKEY

Full RFC 8078 automated DNSSEC key rollover signaling detected (CDS + CDNSKEY)

Key TagAlgorithmDigest TypeDigest
2371 ECDSAP256SHA256 2
CDNSKEY Records:
FlagsProtocolAlgorithmPublic Key
257 3 ECDSAP256SHA256
03 Delivery path · L1 Transport Security Will mail transport resist downgrade and interception? STARTTLS MTA-STS policy TLS-RPT
Mail Transport Security Beta Is mail transport encrypted and verified? Yes DANE/TLSA provides cryptographic transport verification

All 4 server(s) verified: encrypted transport confirmed via direct SMTP probe and DNS policy

Policy Assessment Primary
  • DANE/TLSA records published — mail servers pin TLS certificates via DNSSEC (RFC 7672)
Telemetry
TLS-RPT not configured — domain has no visibility into TLS delivery failures from real senders
Live Probe Supplementary
MX Host STARTTLS TLS Version Cipher Key Exchange Certificate
mxb.global.inbound.cf-emailsecurity.net TLSv1.3 TLS_AES_128_GCM_SHA256 N/A Valid
Expires: 2027-02-17 (183 days)
Issuer: SSL Corporation
mxa-canary.global.inbound.cf-emailsecurity.net TLSv1.3 TLS_AES_128_GCM_SHA256 N/A Invalid
mxb-canary.global.inbound.cf-emailsecurity.net TLSv1.3 TLS_AES_128_GCM_SHA256 N/A Invalid
mxa.global.inbound.cf-emailsecurity.net TLSv1.3 TLS_AES_128_GCM_SHA256 N/A Invalid
Multi-Vantage Probe Results
Split verdict 3 probes, 1 responded
EU (Paris) observed
Partial TLS support
5.225445227s
US-East (Virginia) skipped
8.024s
APAC (Singapore) skipped
8.027s
What Is Measured: Our probe’s TLS 1.3 handshake offers the hybrid post-quantum group X25519MLKEM768 (X25519 combined with ML-KEM-768). The Key Exchange column reports the group each mail server actually negotiated — direct, observed evidence of its post-quantum readiness toward a hybrid-capable client.
Quantum-Safe Hybrid: The session key agreement combines classical X25519 with ML-KEM-768, standardized in FIPS 203 (final, August 2024). This protects the key exchange against “harvest now, decrypt later” collection by a future quantum adversary.
Classical: The server completed the handshake without selecting the offered hybrid group. This is not a deviation — no RFC currently requires post-quantum key exchange. The X25519MLKEM768 group is defined in draft-ietf-tls-ecdhe-mlkem (Standards Track draft, not yet an RFC); the hybrid approach is described in draft-ietf-tls-hybrid-design (IESG-approved Informational). Servers supporting only other hybrid groups also read as Classical here.
Transition Outlook: NIST’s draft transition guidance (NIST IR 8547) projects quantum-vulnerable algorithms being deprecated after 2030 and disallowed after 2035. Hybrid key exchange requires TLS 1.3. This finding is informational and does not affect this domain’s grade.
04 Human-visible identity · L1 Brand & Trust Can this brand be convincingly faked? BIMI & VMC CAA · see Domain Security Protected
Brand Security Can this brand be convincingly faked? No DMARC reject policy enforced (RFC 7489 §6.3), BIMI brand verification active (BIMI Spec), and certificate issuance restricted by CAA (RFC 8659 §4) — all three brand-faking vectors addressed

BIMI BIMI Spec Gold Success VMC SVG

Is the brand identity verified and displayed in inboxes? Yes

BIMI with VMC certificate (from Verified CA)

VMC certificate accessible (from Verified CA) - logo displays in Gmail, Apple Mail, and all major providers.
v=BIMI1; l=https://www.cloudflare.com/cloudflare_1171114652.svg; a=https://www.cloudflare.com/cloudflare_1171114652.pem
BIMI Logo
Logo validated (SVG) View full logo
05 Ownership & attack surface · L1 Infrastructure Intelligence Who operates this domain, and what is exposed? Registrar / RDAP security.txt AI Surface Subdomains
Vulnerability Disclosure Policy (security.txt) Is there a verified way to report security issues? Partial RFC 9116

security.txt found with issues

Contact

https://hackerone.com/cloudflare
https://www.cloudflare.com/abuse/

Expires

Missing (required by RFC 9116 §2.5.5)

Policy

https://www.cloudflare.com/disclosure/
en Canonical URL Hiring
Source: https://cloudflare.com/.well-known/security.txt
Missing required Expires field (RFC 9116 §2.5.5)
AI Surface Scanner Beta Is this domain discoverable by AI — and protected from abuse? Yes

AI governance signals observed

llms.txt llmstxt.org
Is this domain publishing AI-readable brand context? Yes
llms.txt found — domain provides structured context for LLMs View llms.txt
llms-full.txt also found (extended LLM context) View llms-full.txt
AI Crawler Governance (robots.txt) RFC 9309 IETF Draft
Are AI crawlers explicitly allowed or blocked? Not blocked
No AI crawler blocking observed — no blocking directives found in robots.txt View robots.txt
GPTBotChatGPT-UserGoogle-ExtendedAnthropic-AIClaude-WebCCBotPerplexityBot
Content-Usage Directive IETF Draft
Does the site express AI content-usage preferences? Not Configured
No Content-Usage directive detected. The IETF AI Preferences working group is developing a Content-Usage: directive for robots.txt that lets site owners declare whether their content may be used for AI training and inference. This is an active draft, not yet a ratified standard.
Example: Add Content-Usage: ai=no to robots.txt to deny AI training, or Content-Usage: ai=allow to explicitly permit it. Without this directive, AI crawler behavior depends on individual crawler policies and User-agent rules.
AI Recommendation Poisoning
Is this site trying to manipulate AI recommendations? No
No AI recommendation poisoning indicators found
Hidden Prompt Artifacts
Is hidden prompt-injection text present in the source? No
No hidden prompt-like artifacts detected
Evidence Log (3 items)
TypeDetailSeverityConfidence
llms_txt_found llms.txt file found providing structured LLM context info Observed
llms_full_txt_found llms-full.txt also found (extended LLM context) info Observed
robots_txt_no_ai_blocks robots.txt found but no AI-specific blocking directives low Observed
Public Exposure Checks Are sensitive files or secrets exposed? No

No exposed secrets detected in public page source — same-origin, non-intrusive scan of publicly visible page source and scripts.

No exposed secrets, API keys, or credentials were detected in publicly accessible page source or scripts.
What type of scan is this?

This is OSINT (Open Source Intelligence) collection — we check the same publicly accessible URLs that any web browser could visit. No authentication is bypassed, no ports are probed, no vulnerabilities are exploited.

Is this a PCI compliance scan? No. PCI DSS requires scans performed by an Approved Scanning Vendor (ASV) certified by the PCI Security Standards Council. DNS Tool is not an ASV. If you need PCI compliance scanning, engage a certified ASV such as Qualys, Tenable, or Trustwave.

Is this a penetration test? No. Penetration testing involves active exploitation attempts against systems with authorization. Our checks are passive observation of publicly accessible resources — the same methodology used by Shodan, Mozilla Observatory, and other OSINT platforms.

DNS Server Security Hardened

No DNS server misconfigurations found on ns3.cloudflare.com — Nmap NSE probes for zone transfer (AXFR), open recursion (RFC 5358), nameserver identity disclosure, and DNS cache snooping.

Check Result Detail
Zone Transfer (AXFR) Denied Zone transfer denied (correct configuration)
Open Recursion Disabled Recursion disabled (correct configuration)
Nameserver Identity Hidden No nameserver identity information disclosed
Cache Snooping Protected Cache snooping not possible (correct configuration)

Tested nameservers: ns3.cloudflare.com, ns7.cloudflare.com, ns5.cloudflare.com, ns6.cloudflare.com, ns4.cloudflare.com

Nameserver Fleet Matrix Healthy

Analyzed 5 nameserver(s) for cloudflare.com — Per-nameserver reachability, ASN diversity, SOA serial sync, and lame delegation checks.

Nameserver IPv4 IPv6 ASN / Operator UDP TCP AA SOA Serial Anycast Node
ns6.cloudflare.com 162.159.3.11
162.159.5.6 		2400:cb00:2049:1::a29f:506
2400:cb00:2049:1::a29f:30b 		AS13335
Cloudflare, Inc. 		2412182421 119m161· 5ms
ns7.cloudflare.com 162.159.4.8
162.159.6.6 		2400:cb00:2049:1::a29f:408
2400:cb00:2049:1::a29f:606 		AS13335
Cloudflare, Inc. 		2412182421 988m55· 5ms
ns4.cloudflare.com 162.159.1.33
162.159.8.55 		2400:cb00:2049:1::a29f:837
2400:cb00:2049:1::a29f:121 		AS13335
Cloudflare, Inc. 		2412182421 119m200· 5ms
ns5.cloudflare.com 162.159.2.9
162.159.9.55 		2400:cb00:2049:1::a29f:937
2400:cb00:2049:1::a29f:209 		AS13335
Cloudflare, Inc. 		2412182421 988m17· 5ms
ns3.cloudflare.com 162.159.7.226
162.159.0.33 		2400:cb00:2049:1::a29f:7e2
2400:cb00:2049:1::a29f:21 		AS13335
Cloudflare, Inc. 		2412182421 119m143· 5ms
Unique ASNs
1
Unique Operators
1
Unique /24 Prefixes
10
Diversity Score
Fair

1 ASN(s), 10 /24 prefix(es) — consider adding diversity

Infrastructure Intelligence Who hosts this domain and what services power it? Direct

ASN / Network Success

Resolved 0 unique ASN(s) across 4 IP address(es)

IPv4 Mappings:
104.16.132.229 → AS ()
104.16.133.229 → AS ()
IPv6 Mappings:
2606:4700::6810:84e5 → AS ()
2606:4700::6810:85e5 → AS ()

Edge / CDN Success

Domain appears to use direct origin hosting

SaaS TXT Footprint Success 10 services

Detected 10 SaaS verification records

Detects SaaS services that leave DNS TXT verification records (e.g., domain ownership proofs). Does not detect all SaaS platforms — only those indicated by DNS.

ServiceVerification Record
Microsoft MS=ms70274184
Apple apple-domain-verification=DNnWJoArJobFJKhJ
Atlassian atlassian-domain-verification=WxxKyN9aLnjEsoOjUYI6T0bb5vcqmKzaIkC9Rx2QkNb751G3LL/cus8/ZDOgh8xB
Canva canva-site-verification=oOyaVnHC-OiFoR1BPvetNA
Cisco Umbrella cisco-ci-domain-verification=27e926884619804ef987ae4aa1c4168f6b152ada84f4c8bfc74eb2bd2912ad72
Facebook facebook-domain-verification=h9mm6zopj6p2po54woa16m5bskm6oo
Google google-site-verification=C7thfNeXVahkVhniiqTI1iSVnElKR_kBBtnEHkeGDlo
Miro miro-verification=bdd7dfa0a49adfb43ad6ddfaf797633246c07356
Statuspage status-page-domain-verification=r14frwljwbxs
Stripe stripe-verification=5096d01ff2cf194285dd51cae18f24fa9c26dc928cebac3636d462b4c6925623
Traffic & Routing Where does this domain's traffic actually terminate?

AIPv4 Address

104.16.132.229
104.16.133.229
Where the domain points for web traffic

AAAAIPv6 Address

2606:4700::6810:84e5
2606:4700::6810:85e5
IPv6 ready

MXMail Servers

10 mxa.global.inbound.cf-emailsecurity.net.
10 mxb.global.inbound.cf-emailsecurity.net.
5 mxa-canary.global.inbound.cf-emailsecurity.net.
5 mxb-canary.global.inbound.cf-emailsecurity.net.
Priority + mail server for email delivery

SRVServices

No SRV records
No service-specific routing configured
Web: Reachable (2 IPv4, 2 IPv6) Mail: 4 servers Services: None
Subdomain Discovery RFC 6962 Recon LIVE What subdomains and infrastructure are exposed in certificate logs? None found
How did we find these?

No subdomains found via Certificate Transparency logs, DNS probing, or CNAME chain traversal for this domain. No TLS certificates have been issued and no common service names resolve for subdomains of cloudflare.com.

Δ No Propagation Issues: All DNS records are synchronized between resolver and authoritative nameserver.
06 Raw records & reproducibility · L2–L3 Evidence & Verification Can another engineer reproduce every material claim? Analysis Confidence Intelligence Currency What changed Raw record diff Integrity seal Reproduce
Resolver agreement is inconsistent for some protocols, limiting confidence. Data currency and system maturity are adequate.
Accuracy 57% Currency 72/100 Maturity gold
Limiting factor: Resolver agreement is low for this scan — some protocols returned inconsistent results across resolvers
Currentness Excellent TTL Compliance Excellent Completeness Degraded Source Credibility Excellent TTL Relevance Stale
ICuAE Details
DNS data shows some aging or gaps — consider re-scanning for critical decisions

The following DNS record TTLs deviate from recommended values. Incorrect TTLs can cause caching issues, slow propagation, or unnecessary DNS traffic.

Record Type Observed TTL Typical TTL Severity Context
SOA 5 minutes (300s) 1 hour (3600s) high SOA TTL is below typical — observed 5 minutes (300s), typical value is 1 hour (3600s). Short TTLs increase DNS query volume but enable faster propagation. If you are preparing for a migration or need rapid failover, this may be intentional (RFC 1035 §3.2.1). For steady-state production, consider 3600 seconds per NIST SP 800-53 SI-7 relevance guidance. Use the TTL Tuner for profile-specific recommendations.
Provider Note: Cloudflare manages SOA timers automatically. Free/Pro/Business plans cannot modify SOA values. Observed TTL (5 minutes (300s)) is set by Cloudflare, not the zone administrator. See RFC 1912 §2.2 for recommended SOA timer values.
A 5 minutes (300s) 1 hour (3600s) high A TTL is below typical — observed 5 minutes (300s), typical value is 1 hour (3600s). Short TTLs increase DNS query volume but enable faster propagation. If you are preparing for a migration or need rapid failover, this may be intentional (RFC 1035 §3.2.1). For steady-state production, consider 3600 seconds per NIST SP 800-53 SI-7 relevance guidance. Use the TTL Tuner for profile-specific recommendations.
Provider Note: This TTL (5 minutes (300s)) matches Cloudflare's fixed proxied-record TTL. If this record is proxied (orange cloud), the TTL is enforced by Cloudflare and cannot be changed. Disable proxying (gray cloud) to regain TTL control, at the cost of losing Cloudflare's DDoS protection and CDN.
AAAA 5 minutes (300s) 1 hour (3600s) high AAAA TTL is below typical — observed 5 minutes (300s), typical value is 1 hour (3600s). Short TTLs increase DNS query volume but enable faster propagation. If you are preparing for a migration or need rapid failover, this may be intentional (RFC 1035 §3.2.1). For steady-state production, consider 3600 seconds per NIST SP 800-53 SI-7 relevance guidance. Use the TTL Tuner for profile-specific recommendations.
Provider Note: This TTL (5 minutes (300s)) matches Cloudflare's fixed proxied-record TTL. If this record is proxied (orange cloud), the TTL is enforced by Cloudflare and cannot be changed. Disable proxying (gray cloud) to regain TTL control, at the cost of losing Cloudflare's DDoS protection and CDN.
TXT 5 minutes (300s) 1 hour (3600s) high TXT TTL is below typical — observed 5 minutes (300s), typical value is 1 hour (3600s). Short TTLs increase DNS query volume but enable faster propagation. If you are preparing for a migration or need rapid failover, this may be intentional (RFC 1035 §3.2.1). For steady-state production, consider 3600 seconds per NIST SP 800-53 SI-7 relevance guidance. Use the TTL Tuner for profile-specific recommendations.
NS 16087s 1 day (86400s) medium NS TTL is below typical — observed 16087s, typical value is 1 day (86400s). Short TTLs increase DNS query volume but enable faster propagation. If you are preparing for a migration or need rapid failover, this may be intentional (RFC 1035 §3.2.1). For steady-state production, consider 86400 seconds per NIST SP 800-53 SI-7 relevance guidance. Use the TTL Tuner for profile-specific recommendations.
MX 669s 1 hour (3600s) medium MX TTL is below typical — observed 669s, typical value is 1 hour (3600s). Short TTLs increase DNS query volume but enable faster propagation. If you are preparing for a migration or need rapid failover, this may be intentional (RFC 1035 §3.2.1). For steady-state production, consider 3600 seconds per NIST SP 800-53 SI-7 relevance guidance. Use the TTL Tuner for profile-specific recommendations.
CAA 5 minutes (300s) 1 hour (3600s) high CAA TTL is below typical — observed 5 minutes (300s), typical value is 1 hour (3600s). Short TTLs increase DNS query volume but enable faster propagation. If you are preparing for a migration or need rapid failover, this may be intentional (RFC 1035 §3.2.1). For steady-state production, consider 3600 seconds per NIST SP 800-53 SI-7 relevance guidance. Use the TTL Tuner for profile-specific recommendations.

Big Picture Questions

  • How often do you actually change this record? If it hasn’t changed in months, a short TTL is generating unnecessary DNS queries without any benefit.
  • Are you preparing for a migration or IP change? Short TTLs make sense temporarily — but should be raised back to 1 hour (3600s) once the change is complete.
  • Every DNS lookup adds 20–150ms of latency. With a 60s TTL, returning visitors trigger a fresh lookup every minute. With 3600s, they get cached responses for an hour — faster page loads, no extra infrastructure needed.
  • Google runs A records at ~30s because they operate a global anycast network and need to steer traffic dynamically. For a typical website without that infrastructure, copying those TTLs increases query volume with zero upside.
Tune TTL for cloudflare.com
Reference: NIST SP 800-53 SI-7 (Information Integrity) · RFC 8767 (Serve Stale) · RFC 1035 §3.2.1 (TTL semantics) DNS provider detected: Cloudflare — provider-specific RFC compliance notes are shown inline above where applicable.
Primary NS ns3.cloudflare.com
Serial 2412182421
Admin dns.cloudflare.com
Provider Cloudflare
Timer Value RFC 1912 Range
Refresh10000s1,200–43,200s (20 min – 12 hrs)
Retry2400sFraction of Refresh
Expire604800s1,209,600–2,419,200s (14–28 days)
Minimum (Neg. Cache)300s300–86,400s (5 min – 1 day)
Expire: SOA Expire is 7 days (604800s). RFC 1912 §2.2 recommends 1,209,600–2,419,200 seconds (14–28 days). If the primary nameserver becomes unreachable, secondary nameservers will stop serving this zone after only 7 days (604800s). Cloudflare's anycast architecture reduces the practical risk, but this value departs from the RFC recommendation.
RFC 1912 §2.2

Independent RFC compliance assessment for Cloudflare. Each finding cites the specific RFC section and reports what the engineering community consensus is. We report honestly — if a provider deviates from standards, we explain what they did differently and what the RFCs actually say.

SOA Expire below RFC 1912 recommendation RFC 1912 §2.2

Cloudflare sets SOA Expire to 604,800 seconds (7 days). RFC 1912 §2.2 recommends 1,209,600–2,419,200 seconds (14–28 days). This means secondary nameservers stop serving the zone sooner if the primary becomes unreachable. Cloudflare's position is that their anycast architecture makes traditional zone transfer semantics less relevant. SOA timers are not editable on Free, Pro, or Business plans.

Below RFC recommendation
Proxied record TTLs fixed at 300s RFC 2181 §5.2

Cloudflare overrides the zone administrator's TTL to 300 seconds for all proxied (orange-cloud) records. RFC 2181 §5.2 requires TTL uniformity within an RRset but does not mandate a specific value. As the authoritative server, Cloudflare is technically within its rights, but the administrator loses TTL control. This can affect ACME DNS-01 challenges and automation workflows that depend on rapid propagation.

Technically compliant, but overrides administrator intent
Non-standard SOA serial format RFC 1912 §2.2

RFC 1912 recommends YYYYMMDDNN format for SOA serial numbers (e.g., 2026022501). Cloudflare uses a proprietary serial number format that does not encode the date. RFC 1035 only requires the serial to increment on changes, so this is compliant with the mandatory standard but breaks the convention relied on by monitoring tools.

Compliant with RFC 1035, deviates from RFC 1912 convention
Negative cache TTL delays new records RFC 2308 §5

Cloudflare's SOA MINIMUM (negative cache TTL) is 1,800–3,600 seconds (30–60 minutes). This controls how long resolvers cache NXDOMAIN responses. Newly created DNS records — including ACME DNS-01 challenge TXT records for Let's Encrypt — may be invisible for up to 1 hour even after creation. This causes certificate issuance failures for automation tools like cert-manager and Traefik. Workaround: pre-create placeholder records before they're needed. This is RFC-compliant but aggressive compared to the 300–900 seconds common at other providers.

RFC-compliant, but causes real-world automation failures
Historical RFC 2181 §5.2 violation: TTL mismatch in CNAME RRsets RFC 2181 §5.2

In February 2022, Cloudflare's resolver (1.1.1.1) returned CNAME responses with mismatched TTLs within the same RRset — including cases where one TTL was zero and another was non-zero. RFC 2181 §5.2 explicitly states: 'the TTLs of all RRs in an RRSet must be the same.' systemd-resolved (used by Arch Linux, Ubuntu, Fedora, and most modern Linux distributions) correctly rejected these responses per the RFC, causing widespread DNS resolution failures. Cloudflare acknowledged the issue and it appears to have been fixed, but it demonstrated that Cloudflare's DNS infrastructure can deviate from RFC requirements in ways that break compliant resolver implementations.

Was a documented RFC violation — appears resolved
This assessment is based on RFC specifications, provider documentation, and documented incidents from DNS engineering communities. DNS Tool does not have a commercial relationship with any provider listed.
DNS Intelligence What does DNS look like right now — and what changed over time?
DNS Evidence Diff Side-by-side comparison
Resolver Records (Public DNS cache)
Authoritative Records (Source of truth)
A Synchronized 2 / 2 records
104.16.132.229
104.16.133.229
104.16.133.229
104.16.132.229
AAAA Synchronized 2 / 2 records
2606:4700::6810:84e5
2606:4700::6810:84e5
2606:4700::6810:85e5
2606:4700::6810:85e5
CAA RFC 8659 §4 Synchronized 11 / 11 records
0 issue "ssl.com"
0 iodef "mailto:tls-abuse@cloudflare.com"
0 issuewild "pki.goog; cansignhttpexchanges=yes"
0 issue "comodoca.com"
0 issuewild "digicert.com; cansignhttpexchanges=yes"
0 issue "digicert.com; cansignhttpexchanges=yes"
0 issuewild "letsencrypt.org"
0 issue "letsencrypt.org"
0 issue "comodoca.com"
0 issue "pki.goog; cansignhttpexchanges=yes"
0 iodef "mailto:tls-abuse@cloudflare.com"
0 issue "ssl.com"
0 issue "letsencrypt.org"
0 issuewild "comodoca.com"
0 issue "digicert.com; cansignhttpexchanges=yes"
0 issuewild "digicert.com; cansignhttpexchanges=yes"
0 issue "pki.goog; cansignhttpexchanges=yes"
0 issuewild "letsencrypt.org"
0 issuewild "ssl.com"
0 issuewild "pki.goog; cansignhttpexchanges=yes"
0 issuewild "comodoca.com"
0 issuewild "ssl.com"
DMARC _dmarc.cloudflare.com RFC 7489 §6.3 Synchronized 1 / 1 records
v=DMARC1; p=reject; sp=reject; adkim=r; aspf=r; pct=100; rua=mailto:a1c47f179bc04efd8ee4dcd4d85dfc65@dmarc-reports.cloudflare.net,mailto:rua@cloudflare.com
v=DMARC1; p=reject; sp=reject; adkim=r; aspf=r; pct=100; rua=mailto:a1c47f179bc04efd8ee4dcd4d85dfc65@dmarc-reports.cloudflare.net,mailto:rua@cloudflare.com
MX RFC 5321 Synchronized 4 / 4 records
10 mxa.global.inbound.cf-emailsecurity.net.
10 mxa.global.inbound.cf-emailsecurity.net.
10 mxb.global.inbound.cf-emailsecurity.net.
10 mxb.global.inbound.cf-emailsecurity.net.
5 mxa-canary.global.inbound.cf-emailsecurity.net.
5 mxa-canary.global.inbound.cf-emailsecurity.net.
5 mxb-canary.global.inbound.cf-emailsecurity.net.
5 mxb-canary.global.inbound.cf-emailsecurity.net.
NS RFC 1035 Synchronized 5 / 5 records
ns3.cloudflare.com.
ns3.cloudflare.com.
ns4.cloudflare.com.
ns4.cloudflare.com.
ns5.cloudflare.com.
ns5.cloudflare.com.
ns6.cloudflare.com.
ns6.cloudflare.com.
ns7.cloudflare.com.
ns7.cloudflare.com.
SOA RFC 1035 Synchronized 1 / 1 records
ns3.cloudflare.com. dns.cloudflare.com. 2412182421 10000 2400 604800 300
ns3.cloudflare.com. dns.cloudflare.com. 2412182421 10000 2400 604800 300
TXT RFC 7208 §4 28 / 0 records
DirectFedAuthUrl=https://cloudflare-security.cloudflareaccess.com/cdn-cgi/access/sso/saml/dba6756ad312fc13c45f705cf7f5e87f4d658be016c41f950329aa4085b3abc1
—
DirectFedAuthUrl=https://cloudflare-security.cloudflareaccess.com/cdn-cgi/access/sso/saml/ebec933773c69c93420d13e6776adb8c4a190f6281f9d132bcebd7dcb0967bdd
—
MS=ms70274184
—
ZOOM_verify_7LFBvOO9SIigypFG2xRlMA
—
_neqmkgaq1lq9it5s8qmetrhbnu121wb
—
_saml-domain-challenge.2dc00405-79cd-457b-b288-a119c6f0c7b7.71996d53-d178-4ba9-bef4-7f7e46edab74.cloudflare.com=1c8736fd-84b2-4197-985f-3fb2852f2457
—
_wkjc0fot0d7qrvrdt78bxkj2e2o67d2
—
apple-domain-verification=DNnWJoArJobFJKhJ
—
asv=894f6d1f9f83bcf44e4b1bc40bc1c4aa
—
atlassian-domain-verification=WxxKyN9aLnjEsoOjUYI6T0bb5vcqmKzaIkC9Rx2QkNb751G3LL/cus8/ZDOgh8xB
—
canva-site-verification=oOyaVnHC-OiFoR1BPvetNA
—
cisco-ci-domain-verification=27e926884619804ef987ae4aa1c4168f6b152ada84f4c8bfc74eb2bd2912ad72
—
creatopy-domain-verification=97d2ca50-9b6f-4a21-9bdb-fbb630e4cec7
—
databank-domain-verification-hkehd2=fzgu4kmbZwMoW99zENgO4u8NL
—
docker-verification=c578e21c-34fb-4474-9b90-d55ee4cba10c
—
drift-domain-verification=f037808a26ae8b25bc13b1f1f2b4c3e0f78c03e67f24cefdd4ec520efa8e719f
—
facebook-domain-verification=h9mm6zopj6p2po54woa16m5bskm6oo
—
google-site-verification=C7thfNeXVahkVhniiqTI1iSVnElKR_kBBtnEHkeGDlo
—
google-site-verification=ZdlQZLBBAPkxeFTCM1rpiB_ibtGff_JF5KllNKwDR9I
—
liveramp-site-verification=EhH1MqgwbndTWl1AN64hOTKz7hc1s80yUpchLbgpfY0
—
logmein-verification-code=b3433c86-3823-4808-8a7e-58042469f654
—
miro-verification=bdd7dfa0a49adfb43ad6ddfaf797633246c07356
—
onetrust-domain-verification=bd5cd08a1e9644799fdb98ed7d60c9cb
—
status-page-domain-verification=r14frwljwbxs
—
stripe-verification=5096d01ff2cf194285dd51cae18f24fa9c26dc928cebac3636d462b4c6925623
—
stripe-verification=bf1a94e6b16ace2502a4a7fff574a25c8a45291054960c883c59be39d1788db9
—
uber-domain-verification=58086039-150a-42a4-a4be-b4032921aa0f
—
v=spf1 ip4:199.15.212.0/22 ip4:173.245.48.0/20 include:_spf.google.com include:spf1.mcsv.net include:spf.mandrillapp.com include:mail.zendesk.com include:stspg-customer.com include:_spf.salesforce.com -all
—
DNS History Timeline BETA
Your key is sent directly to SecurityTrails and is never stored on our servers. Get an API key
DNS History Timeline BETA

When was a record added, removed, or changed — and could that change be the problem?

Analyze Another Domain

Confirm Your Email Configuration

This tool analyzes DNS records, but to verify actual email delivery, send a test email to Red Sift Investigate. Their tool shows exactly how your emails arrive, including SPF/DKIM/DMARC pass/fail results in the headers.

DATA FRESHNESS & METHODOLOGY

All security-critical records (SPF, DMARC, DKIM, DANE/TLSA, DNSSEC, MTA-STS, TLS-RPT, BIMI, CAA) are queried live from authoritative nameservers and cross-referenced against 5 independent public DNS resolvers (Cloudflare, Google, Quad9, OpenDNS, DNS4EU) at the time of each analysis. No security verdict uses cached data.

Registrar data (RDAP) is cached for up to 24 hours because domain ownership and registration details change infrequently. Certificate Transparency logs (subdomain discovery via RFC 6962) are cached for 1 hour because CT entries are append-only historical records. Sections using cached data are marked with a CACHED badge; live queries show LIVE.

Intelligence Sources

This analysis used 4 DNS resolvers (consensus), reverse DNS (PTR), Team Cymru (ASN attribution), IANA RDAP (registrar), crt.sh (CT logs), and SMTP probing (transport). All using open-standard protocols.

Full List
Verify Report Integrity SHA-3-512 Has this report been altered since generation? Verify below

This cryptographic hash seals the analysis data, domain, timestamp, and tool version into a tamper-evident fingerprint. Any modification to the report data will produce a different hash. This is distinct from the posture hash (used for drift detection) — the integrity hash uniquely identifies this specific report instance.

edb9508953b273d8d55ff47f2351bcc0d7f506f0a70535b71328a14ff7a4c0aae9f5c17513121420198a2a259c5e67d5029ce4710a81ac643a1113c78a2643da
Evaluations reference 12 RFCs. Methods are reproducible using the verification commands provided. Results reflect DNS state at 17 Aug 2026, 20:39 UTC.
Internet Archive — Permanent Record Wayback Machine Can this analysis be independently verified? Archived

This analysis has been automatically submitted to the Internet Archive's Wayback Machine, creating a tamper-evident, third-party-hosted snapshot of the DNS security posture at analysis time. This archived copy is independent of DNS Tool — it provides an independently verifiable record of the analysis at this point in time. Combined with the SHA-3-512 integrity hash, this creates a verifiable chain of evidence for domain security state.

View Archived Snapshot
Snapshot preserved at https://web.archive.org/web/20260817204002/https://dnstool.it-help.tech/analysis/18428/view/E
Download Raw Intelligence Download Checksum (.sha3) Cross-Reference Verification

Download the intelligence dump and verify its integrity, like you would a Kali ISO or any critical artifact. The SHA-3-512 checksum covers every byte of the download — deterministic serialization ensures identical hashes across downloads.

After downloading, verify with any of these commands:

Tip: cd ~/Downloads first (or wherever you saved the files).

OpenSSL + Sidecar (macOS, Linux, WSL) 
cat dns-intelligence-cloudflare.com.json.sha3 && echo '---' && openssl dgst -sha3-512 dns-intelligence-cloudflare.com.json
Python 3 (cross-platform) 
python3 -c "import hashlib; print(hashlib.sha3_512(open('dns-intelligence-cloudflare.com.json','rb').read()).hexdigest())"
sha3sum (coreutils 9+) 
sha3sum -a 512 dns-intelligence-cloudflare.com.json
Compare the output against the .sha3 file or the checksum API at /api/analysis/18428/checksum. Hash algorithm: SHA-3-512 (Keccak, NIST FIPS 202).

Every finding in this report is backed by DNS queries you can run yourself. These vetted one-liners reproduce the exact checks used to build this report for cloudflare.com. Our analysis adds multi-resolver consensus, RFC-based evaluation, and cross-referencing — but the underlying data is always independently verifiable. We are intelligence analysts, not gatekeepers.

DNS Records

Query A records (IPv4) RFC 1035 
dig +noall +answer cloudflare.com A
Query AAAA records (IPv6) RFC 1035 
dig +noall +answer cloudflare.com AAAA
Query MX records (mail servers) RFC 1035 
dig +noall +answer cloudflare.com MX
Query NS records (nameservers) RFC 1035 
dig +noall +answer cloudflare.com NS
Query TXT records RFC 1035 
dig +noall +answer cloudflare.com TXT

Email Authentication

Check SPF record RFC 7208 
dig +short cloudflare.com TXT | grep -i spf
Check DMARC policy RFC 7489 
dig +short _dmarc.cloudflare.com TXT
Check DKIM key for selector 'k1' RFC 6376 
dig +short k1._domainkey.cloudflare.com TXT
Check DKIM key for selector 'mandrill' RFC 6376 
dig +short mandrill._domainkey.cloudflare.com TXT
Check DKIM key for selector 's1' RFC 6376 
dig +short s1._domainkey.cloudflare.com TXT
Check DKIM key for selector 'smtpapi' RFC 6376 
dig +short smtpapi._domainkey.cloudflare.com TXT

Domain Security

Check DNSSEC DNSKEY records RFC 4035 
dig +dnssec +noall +answer cloudflare.com DNSKEY
Check DNSSEC DS records RFC 4035 
dig +noall +answer cloudflare.com DS
Validate DNSSEC chain (requires DNSSEC-validating resolver) RFC 4035 
dig +dnssec +cd cloudflare.com A @1.1.1.1

Transport Security

Check TLSA record for mxa.global.inbound.cf-emailsecurity.net RFC 7672 
dig +noall +answer _25._tcp.mxa.global.inbound.cf-emailsecurity.net TLSA
Check TLSA record for mxb.global.inbound.cf-emailsecurity.net RFC 7672 
dig +noall +answer _25._tcp.mxb.global.inbound.cf-emailsecurity.net TLSA
Check TLSA record for mxa-canary.global.inbound.cf-emailsecurity.net RFC 7672 
dig +noall +answer _25._tcp.mxa-canary.global.inbound.cf-emailsecurity.net TLSA
Check TLSA record for mxb-canary.global.inbound.cf-emailsecurity.net RFC 7672 
dig +noall +answer _25._tcp.mxb-canary.global.inbound.cf-emailsecurity.net TLSA
Verify TLS certificate on primary MX (mxa.global.inbound.cf-emailsecurity.net) RFC 6698 
openssl s_client -starttls smtp -connect mxa.global.inbound.cf-emailsecurity.net:25 -servername mxa.global.inbound.cf-emailsecurity.net 2>/dev/null | openssl x509 -noout -subject -dates
Check MTA-STS DNS record RFC 8461 
dig +short _mta-sts.cloudflare.com TXT
Fetch MTA-STS policy file RFC 8461 
curl -sL https://mta-sts.cloudflare.com/.well-known/mta-sts.txt
Check TLS-RPT record RFC 8460 
dig +short _smtp._tls.cloudflare.com TXT

Brand & Trust

Check BIMI record BIMI Draft 
dig +short default._bimi.cloudflare.com TXT
Check CAA records (certificate authority authorization) RFC 8659 
dig +noall +answer cloudflare.com CAA

DNS Records

Check HTTPS/SVCB records RFC 9460 
dig +noall +answer cloudflare.com HTTPS

Domain Security

Check CDS/CDNSKEY automation records RFC 7344 
dig +noall +answer cloudflare.com CDS

Infrastructure Intelligence

RDAP domain registration lookup RFC 9083 
curl -sL 'https://rdap.org/domain/cloudflare.com' | python3 -m json.tool | head -50

Transport Security

Test STARTTLS on primary MX (mxa.global.inbound.cf-emailsecurity.net) RFC 3207 
openssl s_client -starttls smtp -connect mxa.global.inbound.cf-emailsecurity.net:25 -servername mxa.global.inbound.cf-emailsecurity.net </dev/null 2>/dev/null | head -5

Infrastructure Intelligence

Search Certificate Transparency logs RFC 6962 
curl -s 'https://crt.sh/?q=%25.cloudflare.com&output=json' | python3 -c "import json,sys; [print(e['name_value']) for e in json.load(sys.stdin)]" | sort -u | head -20
Check security.txt RFC 9116 
curl -sL https://cloudflare.com/.well-known/security.txt | head -20

AI Surface

Check for llms.txt 
curl -sI https://cloudflare.com/llms.txt | head -5
Check robots.txt for AI crawler rules 
curl -s https://cloudflare.com/robots.txt | grep -i -E 'GPTBot|ChatGPT|Claude|Anthropic|Google-Extended|CCBot|PerplexityBot'

Infrastructure Intelligence

ASN lookup for 104.16.132.229 (Team Cymru) 
dig +short 229.132.16.104.origin.asn.cymru.com TXT
ASN lookup for 104.16.133.229 (Team Cymru) 
dig +short 229.133.16.104.origin.asn.cymru.com TXT
Commands use dig, openssl, and curl — standard tools available on macOS, Linux, and WSL. Results may vary slightly due to DNS propagation timing and resolver caching.
Intelligence Confidence Audit Engine gold · 9/9 Evaluated
How confident are these results? Each protocol is independently verified against RFC standards. No self-awarded badges.
SPF
Gold 15673 runs
DKIM
Gold 15463 runs
DMARC
Gold 15654 runs
DANE/TLSA
Gold 15445 runs
DNSSEC
Gold 15632 runs
BIMI
Gold 15460 runs
MTA-STS
Gold 15481 runs
TLS-RPT
Gold 15496 runs
CAA
Gold 15493 runs
Maturity: Development → Verified → Consistent → Gold → Gold Master

Appendix: Verification Commands

The core DNS queries behind this report can be independently verified using these standard terminal commands (dig, openssl, curl). DNS Tool adds multi-resolver consensus, RFC-based evaluation, and cross-referencing on top of the raw data shown here.

DNS Records

Query A records (IPv4) (RFC 1035) 
dig +noall +answer cloudflare.com A
Query AAAA records (IPv6) (RFC 1035) 
dig +noall +answer cloudflare.com AAAA
Query MX records (mail servers) (RFC 1035) 
dig +noall +answer cloudflare.com MX
Query NS records (nameservers) (RFC 1035) 
dig +noall +answer cloudflare.com NS
Query TXT records (RFC 1035) 
dig +noall +answer cloudflare.com TXT

Email Authentication

Check SPF record (RFC 7208) 
dig +short cloudflare.com TXT | grep -i spf
Check DMARC policy (RFC 7489) 
dig +short _dmarc.cloudflare.com TXT
Check DKIM key for selector 'k1' (RFC 6376) 
dig +short k1._domainkey.cloudflare.com TXT
Check DKIM key for selector 'mandrill' (RFC 6376) 
dig +short mandrill._domainkey.cloudflare.com TXT
Check DKIM key for selector 's1' (RFC 6376) 
dig +short s1._domainkey.cloudflare.com TXT
Check DKIM key for selector 'smtpapi' (RFC 6376) 
dig +short smtpapi._domainkey.cloudflare.com TXT

Domain Security

Check DNSSEC DNSKEY records (RFC 4035) 
dig +dnssec +noall +answer cloudflare.com DNSKEY
Check DNSSEC DS records (RFC 4035) 
dig +noall +answer cloudflare.com DS
Validate DNSSEC chain (requires DNSSEC-validating resolver) (RFC 4035) 
dig +dnssec +cd cloudflare.com A @1.1.1.1

Transport Security

Check TLSA record for mxa.global.inbound.cf-emailsecurity.net (RFC 7672) 
dig +noall +answer _25._tcp.mxa.global.inbound.cf-emailsecurity.net TLSA
Check TLSA record for mxb.global.inbound.cf-emailsecurity.net (RFC 7672) 
dig +noall +answer _25._tcp.mxb.global.inbound.cf-emailsecurity.net TLSA
Check TLSA record for mxa-canary.global.inbound.cf-emailsecurity.net (RFC 7672) 
dig +noall +answer _25._tcp.mxa-canary.global.inbound.cf-emailsecurity.net TLSA
Check TLSA record for mxb-canary.global.inbound.cf-emailsecurity.net (RFC 7672) 
dig +noall +answer _25._tcp.mxb-canary.global.inbound.cf-emailsecurity.net TLSA
Verify TLS certificate on primary MX (mxa.global.inbound.cf-emailsecurity.net) (RFC 6698) 
openssl s_client -starttls smtp -connect mxa.global.inbound.cf-emailsecurity.net:25 -servername mxa.global.inbound.cf-emailsecurity.net 2>/dev/null | openssl x509 -noout -subject -dates
Check MTA-STS DNS record (RFC 8461) 
dig +short _mta-sts.cloudflare.com TXT
Fetch MTA-STS policy file (RFC 8461) 
curl -sL https://mta-sts.cloudflare.com/.well-known/mta-sts.txt
Check TLS-RPT record (RFC 8460) 
dig +short _smtp._tls.cloudflare.com TXT

Brand & Trust

Check BIMI record (BIMI Draft) 
dig +short default._bimi.cloudflare.com TXT
Check CAA records (certificate authority authorization) (RFC 8659) 
dig +noall +answer cloudflare.com CAA

DNS Records

Check HTTPS/SVCB records (RFC 9460) 
dig +noall +answer cloudflare.com HTTPS

Domain Security

Check CDS/CDNSKEY automation records (RFC 7344) 
dig +noall +answer cloudflare.com CDS

Infrastructure Intelligence

RDAP domain registration lookup (RFC 9083) 
curl -sL 'https://rdap.org/domain/cloudflare.com' | python3 -m json.tool | head -50

Transport Security

Test STARTTLS on primary MX (mxa.global.inbound.cf-emailsecurity.net) (RFC 3207) 
openssl s_client -starttls smtp -connect mxa.global.inbound.cf-emailsecurity.net:25 -servername mxa.global.inbound.cf-emailsecurity.net </dev/null 2>/dev/null | head -5

Infrastructure Intelligence

Search Certificate Transparency logs (RFC 6962) 
curl -s 'https://crt.sh/?q=%25.cloudflare.com&output=json' | python3 -c "import json,sys; [print(e['name_value']) for e in json.load(sys.stdin)]" | sort -u | head -20
Check security.txt (RFC 9116) 
curl -sL https://cloudflare.com/.well-known/security.txt | head -20

AI Surface

Check for llms.txt 
curl -sI https://cloudflare.com/llms.txt | head -5
Check robots.txt for AI crawler rules 
curl -s https://cloudflare.com/robots.txt | grep -i -E 'GPTBot|ChatGPT|Claude|Anthropic|Google-Extended|CCBot|PerplexityBot'

Infrastructure Intelligence

ASN lookup for 104.16.132.229 (Team Cymru) 
dig +short 229.132.16.104.origin.asn.cymru.com TXT
ASN lookup for 104.16.133.229 (Team Cymru) 
dig +short 229.133.16.104.origin.asn.cymru.com TXT

0s

Running Real-Time Scan Telemetry

Most scans complete in less than one minute. Some may take longer.

Markers represent known resolver locations. Anycast routing selects the nearest node — exact routing is internal to each provider.

Pipeline nodes reflect live data as each analysis phase completes.

Telemetry Log 0 polls