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DNS Tool
Engineer's DNS Intelligence Report
Generated 28 Feb 2026, 00:32 UTC
Duration 60.0s
Version v26.27.09
Integrity 4b8b4737770d4cff2fc22e8c10baff079665662b658885c5ef8aecc173013cdf7e646a3ff32b71fbae73b9653bc5f3b758b68262ce0eafb94793e44808483dd5
Subject Domain
isc.org

Engineer's DNS Intelligence Report

isc.org
28 Feb 2026, 00:32 UTC · 60.0s ·v26.27.09 · SHA-3-512: 4b8b✱✱✱✱ Verify
Executive Methodology
Recon Mode Snapshot Re-analyze New Domain
Footprint 2 SaaS Services
DNS Security & Trust Posture
Risk Level: Medium Risk
6 protocols configured, 3 not configured Domain appears to be in deliberate DMARC monitoring phase with aggregate reporting enabled Why we go beyond letter grades
1 recommendation 3 monitoring
Intelligence Currency
Data Currency: Good 77/100
ICuAE Details
Currentness Excellent TTL Compliance Excellent Completeness Degraded Source Credibility Excellent TTL Relevance Degraded
DNS data is mostly current with minor gaps — good intelligence currency

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
NS 2 hours (7200s) 1 day (86400s) high NS TTL is below typical — observed 2 hours (7200s), 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-18 relevance guidance. Use the TTL Tuner for profile-specific recommendations.
MX 5 minutes (300s) 1 hour (3600s) high MX 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-18 relevance guidance. Use the TTL Tuner for profile-specific recommendations.
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-18 relevance guidance. Use the TTL Tuner for profile-specific recommendations.
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-18 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 isc.org
Reference: NIST SP 800-53 SI-7 (Information Integrity) · RFC 8767 (Serve Stale) · RFC 1035 §3.2.1 (TTL semantics) Note: Some DNS providers (e.g., AWS Route 53 alias records, Cloudflare proxied records) enforce fixed TTLs that cannot be modified. If a finding targets a record you cannot edit, it reflects the observed value rather than a configuration error on your part.
Primary NS ns-int.isc.org
Serial 2026022343
Admin hostmaster.isc.org
Provider Unknown
Timer Value RFC 1912 Range
Refresh7200s1,200–43,200s (20 min – 12 hrs)
Retry3600sFraction of Refresh
Expire24796800s1,209,600–2,419,200s (14–28 days)
Minimum (Neg. Cache)3600s300–86,400s (5 min – 1 day)
All SOA timer values are within RFC 1912 recommended ranges.
Suggested Scanner Configuration High Confidence
Based on 17 historical scans of this domain
Parameter Current Suggested Severity Rationale
timeout_seconds 5s 8s low Average scan duration is 44.0s, suggesting DNS responses are slow for this domain. Increasing timeout from 5s to 8s prevents premature resolution failures.
RFC 8767
Suggestions require explicit approval before applying. No automatic changes will be made.
Email Spoofing
Partial
Brand Impersonation
Not Setup
DNS Tampering
Protected
Certificate Control
Configured
Recommended
Move DMARC policy from 'none' to 'quarantine' or 'reject'
Monitoring
DMARC record has configuration warnings — review recommended, External domain fr.dmarcian.com has not authorized isc.org to send DMARC reports (missing isc.org._report._dmarc.fr.dmarcian.com TXT record), External domain ag.dmarcian.com has not authorized isc.org to send DMARC reports (missing isc.org._report._dmarc.ag.dmarcian.com TXT record)
Configured
SPF, DMARC (with warnings), DKIM, TLS-RPT, DNSSEC, CAA
Not Configured
MTA-STS, BIMI, DANE
Priority Actions Achievable posture: Low Risk
High Upgrade DMARC from p=none

Your DMARC policy is monitor-only (p=none). Upgrade to p=quarantine or p=reject after reviewing reports to actively prevent spoofing.

A quarantine or reject policy instructs receivers to take action on failing mail.
TypeTXT
Host_dmarc.isc.org (DMARC policy record)
Valuev=DMARC1; p=quarantine; rua=mailto:dmarc-reports@isc.org
RFC 7489 §6.3
Low Deploy MTA-STS

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

MTA-STS tells sending servers to require TLS when delivering mail to your domain.
TypeTXT
Host_mta-sts.isc.org (MTA-STS policy record)
Valuev=STSv1; id=isc.org
RFC 8461
Registrar (RDAP) OBSERVED LIVE
Tucows Domains Inc.
Where domain was purchased
Email Service Provider
Unknown
Moderately Protected
Web Hosting
Unknown
Where website is hosted
DNS Hosting
Unknown
Where DNS records are edited
Email Security Methodology Can this domain be impersonated by email? Yes DMARC is monitor-only (p=none)

SPF Record RFC 7208 §4 Verified

Does this domain declare who may send email on its behalf? Yes
Success ~all 7/10 lookups

SPF valid with industry-standard soft fail (~all), 7/10 lookups

v=spf1 a mx ip4:149.20.0.0/20 ip6:2001:04F8::0/32 ip6:2001:500:60::65/128 ip4:199.6.1.0/24 ip6:2001:500:6b:2::0/64 include:shops.shopify.com include:servers.mcsv.net include:_spf.salesforce.com include:spf-a.customercenter.net include:spf-b.customercenter.net include:spf-c.customercenter.net ~all
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)
~all is the industry standard. Google, Apple, and most providers default to soft fail. CISA (BOD 18-01) and RFC 7489 confirm that DMARC policy — not SPF alone — is the primary enforcement control. Using ~all allows DKIM to be evaluated before a DMARC decision is made. This domain has DMARC p=none (monitoring only). Enforcing quarantine or reject is recommended to gain real protection.

DMARC Policy RFC 7489 §6.3 Verified

Are spoofed emails rejected or quarantined? Monitoring only
Warning p=none

DMARC in monitoring mode (p=none) - spoofed mail still delivered, no enforcement

v=DMARC1; p=none; sp=reject; rua=mailto:0rzssdyk@ag.dmarcian.com; ruf=mailto:0rzssdyk@fr.dmarcian.com, mailto:dmarcforensic@isc.org; fo=1;
Policy p=none provides no protection - spoofed emails reach inboxes
Forensic reporting (ruf) is configured, but most major providers do not send forensic reports. 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. The DMARCbis draft (draft-ietf-dmarc-dmarcbis) has formally removed ruf= from the specification. Consider removing this tag to simplify your record. RFC 7489 §7.3 — Forensic Reports
Advanced cryptographic posture detected. Domain appears to be in deliberate DMARC monitoring phase with aggregate reporting enabled
RFC 7489 Present — DMARC record published per RFC 7489 §6.3.
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 Verified

Are outbound emails cryptographically signed? Yes — verified
Found

Found DKIM records for 4 selector(s)

k2._domainkey
v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAv2aC2KjGKLOwTweBY5A9RpjsxaBXR9r7OAU6U8/zn92ivImI75naUujWbItRI/QmL1jy5PWGqLwoUA0b90ObWaLDc+i9MtTNmGeWO009hr20fIxhGg6XBT2kjZ1DTThopSe1nAndsupmcBwlQ5Q6LJ+ZAxLcujnPIxM0ZBLmgpkv8u6RfY4eFP8OLvdAW3oSuB0DyLDigQX4Sj8wBO4YIdQH6AAmBeOsidsKAFNFUCpc3vCxtBDR12U+cBg724l3sBkMQ8evnz6idnqxq9QAVYh8k4kJ+RP+6cqTdy7LjIm8xY/bQNpQIpGUAuDo2DjLcCDun9DAI4Q/3z+Q0o9QuQIDAQAB;
k3._domainkey MailChimp
v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsYGiMSn7fsUqSvfSX40x9R1OlRtbNiCY80lHRIlcKx3XDIR7257aUx+q9CSIARdfTL6KCuLGNFx5g9TgVr6png4ajcieSQGtOehBgxnkDN8aAA5TX0FmFrcefJU0JoxLOF09EKgXxhSSHCk/ekVb0PXSboHXoZ9+EI404F1qhcwXXIgHXTaUthHTut2P6BBZhIXIgvDe/w49GchR7MRJqjNb7neEBbYHbgWuBTvvHCg7Gy6m6n9krYK+ROWq3dVvXy9plAGK3ygM+HtjIiMt7arRGMOF0WgDTz7YdN9BGpt6BvXxLnjiQcgS5T9n+cIyPZgiWzDMXNlaEEdKTEKxrwIDAQAB;
zendesk1._domainkey Zendesk
v=DKIM1;t=s;n=core;k=rsa;p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA9IqdLrO3Zr2/56MHt8oQVCQorP0Bl2Fz9sM2tFBnJCdB/HogQmuudEg2xAovCN2PYpw44UijIvPuBoT9vxiv6ZCBJTLJXa82r6ke5rE4tbe9NKFIrVIb9S306cJDrnKFMDb8p0dU/Su0+eUR5gVAOtCuz2L8HAzs5edvsEvD/Fb4ny1RLNSEPZkIQLfGhVxQeWANm3+1Jwb/OBVXV9k0nKpWrpgqcmO7NzroJirp014RQY7rGi60JLUubc6XhvoFQBQrtOAdVlZC5wvfS1bgpq5kQpdP7cajIqWCeqxPTeo0ZUpey2ZcaygEsZz0Z3Gs5wDzyuqd7/ADpr2jNF7ozwIDAQAB
zendesk2._domainkey Zendesk
v=DKIM1; t=s; n=core; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAmiSFNkgXrO3I8aOaPONDZWHv027rkiGIwb838OyXPgvFDEkCV/qGcdXSjZnaVAadrTm/oKnL8WOltP9zB1FLEuKt0fTi5zRyKPE4oIYCnEzXwrGqzjUcCABQBawQVqvXjDOaYh9Lhp8W5PYOLo905vRW7ipyIMDhuzBOJls91/WWXnNK0OwP3RghiisZjA3K2KqtRwf7w6GjNeNuAMNhvcmgAN15d/mhK+dev/hcRbal66RoYyTD8c0F0isahWH0envEX8aj+SBhheNk0/U37dGE+4nFaY5yP9CUlYjFKDSIKZgHzG4Hci3t/RubU58pi6BCrQQdAFvIOeDFeCZ0ywIDAQAB
RFC 6376 Conformant — DKIM keys and signatures conform to RFC 6376 §3.6 (Internet Standard).
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 Verified

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 Verified

Will failures in TLS delivery be reported? Yes — reports configured
Success

TLS-RPT configured - receiving TLS delivery reports

v=TLSRPTv1; rua=mailto:0rzssdyk@tls.us.dmarcian.com

DMARC External Reporting Authorization RFC 7489 §7.1

Are external report receivers authorized? Authorization missing
Warning

2 of 2 external reporting domains missing authorization

External Domain Authorization Auth Record
fr.dmarcian.com Unauthorized —
ag.dmarcian.com Unauthorized —
External domain fr.dmarcian.com has not authorized isc.org to send DMARC reports (missing isc.org._report._dmarc.fr.dmarcian.com TXT record)
External domain ag.dmarcian.com has not authorized isc.org to send DMARC reports (missing isc.org._report._dmarc.ag.dmarcian.com TXT record)

Third-Party Action Required

This authorization record must be created by the external reporting provider, not by you. Per RFC 7489 §7.1, the receiving domain must publish a TXT record to confirm it accepts DMARC reports from your domain.

What to do: Contact your DMARC reporting provider and ask them to publish the authorization TXT record shown above. If you use a managed DMARC service (e.g., Ondmarc, Dmarcian, Valimail), this is typically handled during onboarding — reach out to their support if the record is missing.

Impact if unresolved: Compliant receivers may silently discard aggregate or forensic reports destined for the unauthorized address, reducing your DMARC visibility.

DANE / TLSA Verified Recon Methodology Can mail servers establish identity without a public CA? No
RFC 7672 §3 RFC 6698 §2 Not Configured

No DANE/TLSA records found (checked 2 MX hosts)

DANE (RFC 7672) binds TLS certificates to DNSSEC-signed DNS records, protecting email transport against man-in-the-middle attacks and rogue CAs. It is the primary transport security standard — MTA-STS (RFC 8461) was created as the alternative for domains that cannot deploy DNSSEC. Over 1 million domains use DANE globally, including Microsoft Exchange Online, Proton Mail, and Fastmail. Best practice: deploy both for defense in depth.
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 has neither DANE nor MTA-STS. Mail transport relies on opportunistic TLS without policy enforcement, leaving it vulnerable to downgrade attacks. Deploy DANE (RFC 7672) with DNSSEC for the strongest protection, or MTA-STS (RFC 8461) if DNSSEC is not feasible.

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).

Brand Security Can this brand be convincingly faked? Likely DMARC is monitor-only p=none (RFC 7489 §6.3) — spoofed mail is not blocked, brand faking is trivial

BIMI BIMI Spec Verified Warning

Is the brand identity verified and displayed in inboxes? No

No BIMI record found

CAA RFC 8659 §4 Verified Success IODEF

Does this domain restrict who can issue TLS certificates? Yes

CAA configured - only certainly.com, Sectigo, GlobalSign, Let's Encrypt, pki.goog, DigiCert can issue certificates (wildcard issuance: trust-provider.com, certainly.com, Sectigo, usertrust.com, GlobalSign per RFC 8659 §4.3)

Authorized CAs: certainly.com Sectigo GlobalSign Let's Encrypt pki.goog DigiCert
0 iodef "mailto:hostmaster@isc.org"
0 issue "letsencrypt.org"
0 issue "pki.goog"
0 issue "Digicert.com"
0 issue "certainly.com"
0 issue "sectigo.com"
0 issuewild "globalsign.com"
0 issuewild "trust-provider.com"
0 issue "globalsign.com"
0 issue "comodoca.com"
0 issuewild "certainly.com"
0 issuewild "sectigo.com"
0 issuewild "usertrust.com"
0 issuewild "comodoca.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.
Vulnerability Disclosure Policy (security.txt) Is there a verified way to report security issues? No RFC 9116

No security.txt found

A security.txt file at /.well-known/security.txt provides security researchers with a standardized way to report vulnerabilities. See securitytxt.org for a generator.
AI Surface Scanner Beta Is this domain discoverable by AI — and protected from abuse? No

No AI governance measures detected

llms.txt llmstxt.org
Is this domain publishing AI-readable brand context? No
No llms.txt found
No llms-full.txt found
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
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 (1 item)
TypeDetailSeverityConfidence
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.
Sources scanned (3)
  • http://isc.org/
  • https://isc.org/plugins/modernizr/modernizr-custom.js
  • https://isc.org/js/bundle.js
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 ns2.isc.org — 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: ns2.isc.org, ns1.isc.org, ns.isc.afilias-nst.info, ns3.isc.org, nsp.dnsnode.net

Delegation Consistency 4 Issues

Delegation consistency: 4 issue(s) found — Parent/child NS delegation alignment: DS↔DNSKEY, glue records, TTL drift, SOA serial sync.

Findings:
  • In-bailiwick NS ns1.isc.org has no glue records at parent — resolution may fail
  • In-bailiwick NS ns2.isc.org has no glue records at parent — resolution may fail
  • In-bailiwick NS ns3.isc.org 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
7250 13 7250 13

Glue Record Completeness Incomplete

NameserverIn-BailiwickIPv4 GlueIPv6 GlueStatus
ns.isc.afilias-nst.info No N/A N/A OK
ns1.isc.org Missing
ns2.isc.org Missing
ns3.isc.org Missing
nsp.dnsnode.net No N/A N/A OK

NS TTL Comparison Drift

Child TTL: 7200s Drift: 0s

SOA Serial Consistency Consistent

ns.isc.afilias-nst.info: 2.026022343e+09
ns1.isc.org: 2.026022343e+09
ns2.isc.org: 2.026022343e+09
ns3.isc.org: 2.026022343e+09
nsp.dnsnode.net: 2.026022343e+09
Nameserver Fleet Matrix Healthy

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

Nameserver IPv4 IPv6 ASN / Operator UDP TCP AA SOA Serial
nsp.dnsnode.net 194.58.198.32 2a01:3f1:3032::53 AS56908 2026022343
ns.isc.afilias-nst.info 199.254.63.254 2001:500:2c::254 AS12041 2026022343
ns3.isc.org 51.75.79.143 2001:41d0:701:1100::2c92 AS16276
OVH SAS 		2026022343
ns2.isc.org 199.6.1.52 2001:500:60:d::52 AS30132 2026022343
ns1.isc.org 149.20.2.26 2001:500:6b:2::26 AS27321 2026022343
Unique ASNs
5
Unique Operators
1
Unique /24 Prefixes
5
Diversity Score
Good

5 ASNs, 5 /24 prefixes across 5 nameservers

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 27566 ECDSA P-256/SHA-256 256 bits
KSK 7250 ECDSA P-256/SHA-256 256 bits

RRSIG Signatures 1 Signature

TypeKey TagExpiryStatus
SOA 27566 2026-03-13T20:52:00Z Active

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
Mail Transport Security Beta Is mail transport encrypted and verified? Partially TLS reporting is configured but no transport enforcement policy is active

Transport security inferred from 1 signal(s) — no enforcement policy active

Policy Assessment Primary
  • TLS-RPT configured — domain monitors TLS delivery failures (RFC 8460)
Telemetry
TLS-RPT configured — domain receives reports about TLS delivery failures from sending mail servers (RFC 8460)
Reporting to: mailto:0rzssdyk@tls.us.dmarcian.com
Live Probe Supplementary
Skipped — Remote probe failed (connection failed — probe may be offline) and local port 25 is blocked. Transport security is assessed via DNS policy records per NIST SP 800-177 Rev. 1.
Infrastructure Intelligence Who hosts this domain and what services power it? Direct

ASN / Network Success

Resolved 0 unique ASN(s) across 8 IP address(es)

IPv4 Mappings:
151.101.66.217 → AS ()
151.101.194.217 → AS ()
151.101.2.217 → AS ()
151.101.130.217 → AS ()
IPv6 Mappings:
2a04:4e42:600::729 → AS ()
2a04:4e42:400::729 → AS ()
2a04:4e42::729 → AS ()
2a04:4e42:200::729 → AS ()

Edge / CDN Success

Domain appears to use direct origin hosting

SaaS TXT Footprint Success 2 services

2 SaaS services detected via DNS TXT 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
Google Workspace google-site-verification=wg4m8dWi3XVPRYmtBoy6xSKp3juhxIWa6UdxjZkNQCg
Microsoft 365 MS=2583E0E0DCCBF33EC6DAFF0B4BFBAF78FFCF7AD0
Domain Security Methodology Can DNS responses be tampered with in transit? No DNSSEC signed and validated, cryptographic chain of trust verified

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

DNSSEC fully configured and validated — AD (Authenticated Data) flag set by resolver 8.8.8.8 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 authenticated and tamper-proof.
AD Flag: Validated - Resolver (8.8.8.8) confirmed cryptographic signatures
DS Record (at registrar):
7250 13 2 A30B3F78B6DDE9A4A9A2AD0C805518B4F49EC62E7D3F4531D33DE697CDA01CB2

NS Delegation Verified

5 nameserver(s) configured

Nameservers: ns.isc.afilias-nst.info ns1.isc.org ns2.isc.org ns3.isc.org nsp.dnsnode.net
Enterprise DNS (Mixed Configuration)
3 of 5 nameservers are dedicated (isc.org-branded), 2 use external provider(s). This pattern is common in large organizations using split-horizon DNS or maintaining redundancy across internal and external infrastructure.
Dedicated (organization-branded): ns1.isc.org ns2.isc.org ns3.isc.org External provider: ns.isc.afilias-nst.info nsp.dnsnode.net
Multi-Resolver Verification Recon: Discrepancy detected - Some resolvers returned different results (1 difference found)
Resolver Differences:
TXT: OpenDNS returned different results: [F8C4EB9011 MS=2583E0E0DCCBF33EC6DAFF0B4BFBAF78FFCF7AD0 _globalsign-domain-verification=ckxXdoIq27XGYE4ATbBYQOBeV7PTJWRxYe-PXDyzMX google-site-verification=6v652rgkk_kI6Ky32iGdxqXjQ4_BAd5DYKsrnRXKUiE google-site-verification=grXE1SbXWNed6C5yQgI8fwxgucE0DppnbICbhZr9qG0 google-site-verification=wg4m8dWi3XVPRYmtBoy6xSKp3juhxIWa6UdxjZkNQCg]
This may indicate DNS propagation in progress or geo-based DNS routing.

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

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

Key TagAlgorithmDigest TypeDigest
7250 ECDSAP256SHA256 2
CDNSKEY Records:
FlagsProtocolAlgorithmPublic Key
257 3 ECDSAP256SHA256
Traffic & Routing Where does this domain's traffic actually terminate?

AIPv4 Address

151.101.66.217
151.101.194.217
151.101.2.217
151.101.130.217
Where the domain points for web traffic

AAAAIPv6 Address

2a04:4e42:600::729
2a04:4e42:400::729
2a04:4e42::729
2a04:4e42:200::729
IPv6 ready

MXMail Servers

5 mx.pao1.isc.org.
10 mx.ams1.isc.org.
Priority + mail server for email delivery

SRVServices

No SRV records
No service-specific routing configured
Web: Reachable (4 IPv4, 4 IPv6) Mail: 2 servers Services: None
Subdomain Discovery RFC 6962 Recon LIVE What subdomains and infrastructure are exposed in certificate logs? 81 subdomains discovered
How did we find these?
118 unique certificates 81 current 0 expired 3 CNAMEs Source: Certificate Transparency + DNS Intelligence
Subdomains discovered via CT logs (RFC 6962), DNS probing of common service names, and CNAME chain traversal.
Wildcard certificate detected: *.isc.org Active 2 certs 1 CA:
No explicit SANs found on wildcard certificates. Subdomains covered by this wildcard won't appear individually in CT logs (RFC 6962).
DNS probing and CNAME chain traversal were used to discover additional subdomains below.
Certificate Authority Diversity (1 CA observed across CT log history)
Certificate Authority Certs First Issued Last Issued Status
118 2025-02-25 2026-02-27 Active
Subdomain Source Status Provider / CNAME Certificates First Seen Issuer(s)
acme.aws.isc.org CT Log Current — 1 2025-12-18T14:57:02Z
altops.isc.org CT Log Current — 2 2025-12-17T20:58:53Z
asteriskbsd.isc.org CT Log Current — 4 2025-12-24T14:45:36Z
atlas-vis.isc.org CT Log Current — 2 2025-12-29T11:45:44Z
bikeshed.isc.org CT Log Current — 4 2025-12-03T14:59:36Z
bind.isc.org
80/tcp tcpwrapped 443/tcp tcpwrapped
CT Log Current — 1 2026-01-03T03:52:36Z
bugs.isc.org CT Log Current — 3 2025-12-04T08:31:29Z
cloak.isc.org CT Log Current — 2 2025-12-21T06:23:15Z
clock.isc.org CT Log Current clockisc.ntp.org 1 2026-01-03T05:01:59Z
crowsnest-oak1.isc.org CT Log Current — 3 2025-12-11T15:24:01Z
crowsnest.isc.org CT Log Current crowsnest-oak1.isc.org 3 2025-12-11T15:24:01Z
dagger.isc.org CT Log Current — 1 2026-01-02T13:28:28Z
demo.stork.isc.org CT Log Current — 2 2026-01-21T15:07:56Z
dhcp.aws.isc.org CT Log Current — 1 2026-01-26T23:49:39Z
dhcp.isc.org CT Log Current — 1 2026-01-26T23:50:48Z
docs.bind.isc.org
80/tcp Cloudflare http proxy 443/tcp Cloudflare http proxy
CT Log Current readthedocs.io 2 2026-01-02T10:26:54Z
docs.isc.org DNS Current — 2 2025-02-25 —
docs.kea.isc.org CT Log Current readthedocs.io 2 2025-12-31T21:49:25Z
docs.stork.isc.org CT Log Current — 2 2025-12-31T21:49:24Z
downloads.isc.org DNS Current dualstack.osff2.map.fastly.net 2 2025-02-25 —
ednscomp.isc.org CT Log Current — 2 2025-12-24T13:12:22Z
etherpad.isc.org
80/tcp Apache httpd 443/tcp Apache httpd
CT Log Current — 2 2025-12-16T16:24:56Z
ftp.isc.org CT Log Current ftp2.isc.org 2 2025-12-22T11:57:29Z
ftp2.isc.org CT Log Current — 2 2025-12-22T11:57:29Z
gitlab-autoscaling-instance-runner-manager-test.aws.isc.org CT Log Current — 2 2025-12-04T15:14:38Z
gitlab-pages.isc.org CT Log Current — 2 2025-12-07T23:12:38Z
gitlab.isc.org CT Log Current — 2 2025-12-15T01:32:04Z
int.sso.isc.org CT Log Current — 2 2025-12-07T09:57:51Z
jenkins.aws.isc.org CT Log Current — 2 2026-01-24T21:20:39Z
jenkins.isc.org CT Log Current — 2 2025-12-30T07:00:01Z
jobs.isc.org CT Log Current — 1 2026-01-16T04:48:36Z
kb.isc.org CT Log Current lb-cdmz1.document360.io 4 2025-12-08T23:15:36Z
kea.isc.org CT Log Current — 1 2026-01-03T03:52:36Z
lists.isc.org CT Log Current — 3 2025-12-22T11:40:28Z
mattermost.isc.org CT Log Current — 2 2025-12-15T01:32:04Z
monitor.isc.org CT Log Current — 2 2025-12-11T15:24:01Z
mta-sts.isc.org CT Log Current web.isc.org 2 2025-12-29T21:21:36Z
mx.ams1.isc.org CT Log Current — 2 2026-01-09T00:00:00Z
mx.pao1.isc.org CT Log Current — 1 2025-07-25T00:00:00Z
nagios.isc.org CT Log Current crowsnest-oak1.isc.org 2 2025-12-11T15:24:01Z
ns1.isc.org DNS Current — 2 2025-02-25 —
ns2.isc.org DNS Current — 2 2025-02-25 —
ns3.isc.org DNS Current — 2 2025-02-25 —
ops.isc.org CT Log Current — 4 2025-12-17T20:58:47Z
packages.aws.isc.org CT Log Current — 1 2025-12-12T23:12:39Z
pad.isc.org CT Log Current — 2 2025-12-16T16:24:56Z
pandora.isc.org CT Log Current — 1 2026-01-09T02:13:11Z
perflab.isc.org CT Log Current web.isc.org 2 2025-12-29T21:17:09Z
poudriere-pkb.isc.org CT Log Current — 2 2025-12-12T01:24:45Z
poudriere-src.isc.org CT Log Current — 2 2025-12-12T21:55:43Z
registry.gitlab.isc.org CT Log Current — 2 2025-12-15T01:32:04Z
repo.isc.org CT Log Current — 2 2025-12-15T09:21:51Z
reports.kea.isc.org CT Log Current gitlab-pages.isc.org 1 2026-01-27T18:22:37Z
rssac-stats.isc.org CT Log Current rssac-us.f.root-servers.org 2 2025-12-25T09:03:54Z
shop.isc.org CT Log Current shops.myshopify.com 4 2025-12-06T01:51:04Z
sprocket.isc.org CT Log Current — 1 2026-01-21T06:06:44Z
sso.isc.org
80/tcp Apache httpd 443/tcp Apache httpd
CT Log Current — 3 2025-12-22T14:04:37Z
ssotest.isc.org CT Log Current — 1 2026-01-17T16:23:20Z
stork.isc.org
80/tcp tcpwrapped 443/tcp tcpwrapped
CT Log Current — 1 2026-01-12T03:42:40Z
stork.lab.isc.org CT Log Current — 1 2026-01-24T00:56:00Z
support-eu.isc.org CT Log Current — 2 2026-02-03T01:33:08Z
support.isc.org CT Log Current — 2 2026-01-21T14:11:43Z
support5.isc.org CT Log Current — 2 2026-01-21T14:11:43Z
supportbeta.isc.org CT Log Current — 3 2025-12-20T04:03:06Z
techsupport.isc.org CT Log Current — 2 2026-01-21T14:11:43Z
users-int.isc.org CT Log Current — 2 2025-12-15T00:57:19Z
users.isc.org CT Log Current — 2 2025-12-15T00:57:15Z
vcenter.isc.org CT Log Current — 1 2025-03-18T00:00:00Z
victor.isc.org CT Log Current — 1 2026-01-06T21:37:05Z
vpn.isc.org DNS Current — 2 2025-02-25 —
web.isc.org CT Log Current — 2 2025-12-29T21:26:34Z
website.lab.isc.org CT Log Current — 1 2026-01-03T04:02:38Z
wiki-eu.isc.org CT Log Current — 2 2026-01-22T14:03:42Z
wiki.isc.org CT Log Current — 3 2025-12-14T05:17:59Z
www.isc.org DNS Current isc.map.fastlydns.net 2 2025-02-25 —
www.jobs.isc.org CT Log Current secure.recruitee.com 1 2026-01-19T23:18:42Z
www.mx.ams1.isc.org CT Log Current — 2 2026-01-09T00:00:00Z
www.mx.pao1.isc.org CT Log Current — 1 2025-07-25T00:00:00Z
www.vcenter.isc.org CT Log Current — 1 2025-03-18T00:00:00Z
www2.isc.org DNS Current dualstack.osff2.map.fastly.net 2 2025-02-25 —
zabbix.aws.isc.org CT Log Current — 1 2026-01-26T23:55:39Z
Export Recon (CSV)
Δ Changes Detected: TXT Resolver ≠ Authoritative (TTL / CDN rotation / recent change)
Risk: Low - typically resolves within TTL
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 4 / 4 records
151.101.66.217
151.101.66.217
151.101.194.217
151.101.194.217
151.101.2.217
151.101.2.217
151.101.130.217
151.101.130.217
AAAA Synchronized 4 / 4 records
2a04:4e42:600::729
2a04:4e42:400::729
2a04:4e42:400::729
2a04:4e42:600::729
2a04:4e42::729
2a04:4e42::729
2a04:4e42:200::729
2a04:4e42:200::729
CAA RFC 8659 §4 Synchronized 14 / 14 records
0 issue "Digicert.com"
0 issue "certainly.com"
0 issuewild "trust-provider.com"
0 issue "comodoca.com"
0 issue "comodoca.com"
0 issuewild "globalsign.com"
0 issue "globalsign.com"
0 issuewild "usertrust.com"
0 issuewild "usertrust.com"
0 issuewild "certainly.com"
0 issue "certainly.com"
0 iodef "mailto:hostmaster@isc.org"
0 issuewild "sectigo.com"
0 issue "pki.goog"
0 issuewild "certainly.com"
0 issuewild "comodoca.com"
0 iodef "mailto:hostmaster@isc.org"
0 issue "letsencrypt.org"
0 issuewild "globalsign.com"
0 issue "Digicert.com"
0 issuewild "comodoca.com"
0 issue "globalsign.com"
0 issue "pki.goog"
0 issue "sectigo.com"
0 issue "sectigo.com"
0 issuewild "trust-provider.com"
0 issue "letsencrypt.org"
0 issuewild "sectigo.com"
DMARC _dmarc.isc.org RFC 7489 §6.3 Synchronized 1 / 1 records
v=DMARC1; p=none; sp=reject; rua=mailto:0rzssdyk@ag.dmarcian.com; ruf=mailto:0rzssdyk@fr.dmarcian.com, mailto:dmarcforensic@isc.org; fo=1;
v=DMARC1; p=none; sp=reject; rua=mailto:0rzssdyk@ag.dmarcian.com; ruf=mailto:0rzssdyk@fr.dmarcian.com, mailto:dmarcforensic@isc.org; fo=1;
MX RFC 5321 Synchronized 2 / 2 records
5 mx.pao1.isc.org.
5 mx.pao1.isc.org.
10 mx.ams1.isc.org.
10 mx.ams1.isc.org.
NS RFC 1035 Synchronized 5 / 5 records
ns.isc.afilias-nst.info.
ns.isc.afilias-nst.info.
nsp.dnsnode.net.
nsp.dnsnode.net.
ns2.isc.org.
ns2.isc.org.
ns3.isc.org.
ns1.isc.org.
ns1.isc.org.
ns3.isc.org.
SOA RFC 1035 Synchronized 1 / 1 records
ns-int.isc.org. hostmaster.isc.org. 2026022343 7200 3600 24796800 3600
ns-int.isc.org. hostmaster.isc.org. 2026022343 7200 3600 24796800 3600
TLS-RPT _smtp._tls.isc.org RFC 8460 §3 Synchronized 1 / 1 records
v=TLSRPTv1; rua=mailto:0rzssdyk@tls.us.dmarcian.com
v=TLSRPTv1; rua=mailto:0rzssdyk@tls.us.dmarcian.com
TXT RFC 7208 §4 Propagating 7 / 3 records
google-site-verification=wg4m8dWi3XVPRYmtBoy6xSKp3juhxIWa6UdxjZkNQCg
google-site-verification=grXE1SbXWNed6C5yQgI8fwxgucE0DppnbICbhZr9qG0
google-site-verification=grXE1SbXWNed6C5yQgI8fwxgucE0DppnbICbhZr9qG0
v=spf1 a mx ip4:149.20.0.0/20 ip6:2001:04F8::0/32 ip6:2001:500:60::65/128 ip4:199.6.1.0/24 ip6:2001:500:6b:2::0/64 include:shops.shopify.com include:servers.mcsv.net include:_spf.salesforce.com include:spf-a.customercenter.net include:spf-b.customercenter.net include:spf-c.customercenter.net ~all
_globalsign-domain-verification=ckxXdoIq27XGYE4ATbBYQOBeV7PTJWRxYe-PXDyzMX
F8C4EB9011
F8C4EB9011
—
v=spf1 a mx ip4:149.20.0.0/20 ip6:2001:04F8::0/32 ip6:2001:500:60::65/128 ip4:199.6.1.0/24 ip6:2001:500:6b:2::0/64 include:shops.shopify.com include:servers.mcsv.net include:_spf.salesforce.com include:spf-a.customercenter.net include:spf-b.customercenter.net include:spf-c.customercenter.net ~all
—
google-site-verification=6v652rgkk_kI6Ky32iGdxqXjQ4_BAd5DYKsrnRXKUiE
—
MS=2583E0E0DCCBF33EC6DAFF0B4BFBAF78FFCF7AD0
—
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.

4b8b4737770d4cff2fc22e8c10baff079665662b658885c5ef8aecc173013cdf7e646a3ff32b71fbae73b9653bc5f3b758b68262ce0eafb94793e44808483dd5
Evaluations reference 12 RFCs. Methods are reproducible using the verification commands provided. Results reflect DNS state at 28 Feb 2026, 00:32 UTC.
Download Raw Intelligence Download Checksum (.sha3)

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-isc.org.json.sha3 && echo '---' && openssl dgst -sha3-512 dns-intelligence-isc.org.json
Python 3 (cross-platform) 
python3 -c "import hashlib; print(hashlib.sha3_512(open('dns-intelligence-isc.org.json','rb').read()).hexdigest())"
sha3sum (coreutils 9+) 
sha3sum -a 512 dns-intelligence-isc.org.json
Compare the output against the .sha3 file or the checksum API at /api/analysis/5003/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 isc.org. 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 isc.org A
Query AAAA records (IPv6) RFC 1035 
dig +noall +answer isc.org AAAA
Query MX records (mail servers) RFC 1035 
dig +noall +answer isc.org MX
Query NS records (nameservers) RFC 1035 
dig +noall +answer isc.org NS
Query TXT records RFC 1035 
dig +noall +answer isc.org TXT

Email Authentication

Check SPF record RFC 7208 
dig +short isc.org TXT | grep -i spf
Check DMARC policy RFC 7489 
dig +short _dmarc.isc.org TXT
Check DKIM key for selector 'k2' RFC 6376 
dig +short k2._domainkey.isc.org TXT
Check DKIM key for selector 'k3' RFC 6376 
dig +short k3._domainkey.isc.org TXT
Check DKIM key for selector 'zendesk1' RFC 6376 
dig +short zendesk1._domainkey.isc.org TXT
Check DKIM key for selector 'zendesk2' RFC 6376 
dig +short zendesk2._domainkey.isc.org TXT

Domain Security

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

Transport Security

Check TLSA record for mx.pao1.isc.org RFC 7672 
dig +noall +answer _25._tcp.mx.pao1.isc.org TLSA
Check TLSA record for mx.ams1.isc.org RFC 7672 
dig +noall +answer _25._tcp.mx.ams1.isc.org TLSA
Verify TLS certificate on primary MX (mx.pao1.isc.org) RFC 6698 
openssl s_client -starttls smtp -connect mx.pao1.isc.org:25 -servername mx.pao1.isc.org 2>/dev/null | openssl x509 -noout -subject -dates
Check MTA-STS DNS record RFC 8461 
dig +short _mta-sts.isc.org TXT
Fetch MTA-STS policy file RFC 8461 
curl -sL https://mta-sts.isc.org/.well-known/mta-sts.txt
Check TLS-RPT record RFC 8460 
dig +short _smtp._tls.isc.org TXT

Brand & Trust

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

DNS Records

Check HTTPS/SVCB records RFC 9460 
dig +noall +answer isc.org HTTPS

Domain Security

Check CDS/CDNSKEY automation records RFC 7344 
dig +noall +answer isc.org CDS

Infrastructure Intelligence

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

Transport Security

Test STARTTLS on primary MX (mx.pao1.isc.org) RFC 3207 
openssl s_client -starttls smtp -connect mx.pao1.isc.org:25 -servername mx.pao1.isc.org </dev/null 2>/dev/null | head -5

Infrastructure Intelligence

Search Certificate Transparency logs RFC 6962 
curl -s 'https://crt.sh/?q=%25.isc.org&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://isc.org/.well-known/security.txt | head -20

AI Surface

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

Infrastructure Intelligence

ASN lookup for 151.101.66.217 (Team Cymru) 
dig +short 217.66.101.151.origin.asn.cymru.com TXT
ASN lookup for 151.101.194.217 (Team Cymru) 
dig +short 217.194.101.151.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 Verified · 9/9 Evaluated
How confident are these results? Each protocol is independently verified against RFC standards. No self-awarded badges.
SPF
Verified 4884 runs
DKIM
Verified 4702 runs
DMARC
Verified 4867 runs
DANE/TLSA
Verified 4686 runs
DNSSEC
Verified 4865 runs
BIMI
Verified 4701 runs
MTA-STS
Verified 4704 runs
TLS-RPT
Verified 4706 runs
CAA
Verified 4698 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 isc.org A
Query AAAA records (IPv6) (RFC 1035) 
dig +noall +answer isc.org AAAA
Query MX records (mail servers) (RFC 1035) 
dig +noall +answer isc.org MX
Query NS records (nameservers) (RFC 1035) 
dig +noall +answer isc.org NS
Query TXT records (RFC 1035) 
dig +noall +answer isc.org TXT

Email Authentication

Check SPF record (RFC 7208) 
dig +short isc.org TXT | grep -i spf
Check DMARC policy (RFC 7489) 
dig +short _dmarc.isc.org TXT
Check DKIM key for selector 'k2' (RFC 6376) 
dig +short k2._domainkey.isc.org TXT
Check DKIM key for selector 'k3' (RFC 6376) 
dig +short k3._domainkey.isc.org TXT
Check DKIM key for selector 'zendesk1' (RFC 6376) 
dig +short zendesk1._domainkey.isc.org TXT
Check DKIM key for selector 'zendesk2' (RFC 6376) 
dig +short zendesk2._domainkey.isc.org TXT

Domain Security

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

Transport Security

Check TLSA record for mx.pao1.isc.org (RFC 7672) 
dig +noall +answer _25._tcp.mx.pao1.isc.org TLSA
Check TLSA record for mx.ams1.isc.org (RFC 7672) 
dig +noall +answer _25._tcp.mx.ams1.isc.org TLSA
Verify TLS certificate on primary MX (mx.pao1.isc.org) (RFC 6698) 
openssl s_client -starttls smtp -connect mx.pao1.isc.org:25 -servername mx.pao1.isc.org 2>/dev/null | openssl x509 -noout -subject -dates
Check MTA-STS DNS record (RFC 8461) 
dig +short _mta-sts.isc.org TXT
Fetch MTA-STS policy file (RFC 8461) 
curl -sL https://mta-sts.isc.org/.well-known/mta-sts.txt
Check TLS-RPT record (RFC 8460) 
dig +short _smtp._tls.isc.org TXT

Brand & Trust

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

DNS Records

Check HTTPS/SVCB records (RFC 9460) 
dig +noall +answer isc.org HTTPS

Domain Security

Check CDS/CDNSKEY automation records (RFC 7344) 
dig +noall +answer isc.org CDS

Infrastructure Intelligence

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

Transport Security

Test STARTTLS on primary MX (mx.pao1.isc.org) (RFC 3207) 
openssl s_client -starttls smtp -connect mx.pao1.isc.org:25 -servername mx.pao1.isc.org </dev/null 2>/dev/null | head -5

Infrastructure Intelligence

Search Certificate Transparency logs (RFC 6962) 
curl -s 'https://crt.sh/?q=%25.isc.org&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://isc.org/.well-known/security.txt | head -20

AI Surface

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

Infrastructure Intelligence

ASN lookup for 151.101.66.217 (Team Cymru) 
dig +short 217.66.101.151.origin.asn.cymru.com TXT
ASN lookup for 151.101.194.217 (Team Cymru) 
dig +short 217.194.101.151.origin.asn.cymru.com TXT
Running Multi-Source Intelligence Audit

isc.org

0s
DNS records — Cloudflare, Google, Quad9, OpenDNS, DNS4EU
Email auth — SPF, DMARC, DKIM selectors
DNSSEC chain of trust & DANE/TLSA
Certificate Transparency & subdomain discovery
SMTP transport & STARTTLS verification
MTA-STS, TLS-RPT, BIMI, CAA
Registrar & infrastructure analysis
Intelligence Classification & Interpretation

Every result includes terminal commands you can run to independently verify the underlying data. No proprietary magic.