ProfessionalNetwork & DNSToolkit

Fast DNS diagnostics, network checks, security tools and utilities — no captcha, no friction, always free.

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DNS NODA Check DNS Lookup Tool Reverse DNS DNSSEC Checker DNS Propagation DNS Blacklist Checker WHOIS Lookup

Network IP Lookup Tool Online Ping Test Online Traceroute Tool MTR Online (My Traceroute) Online Port Scanner / Checker ASN Lookup

HTTP & IP HTTP Headers Checker SSL Certificate Checker Redirect Tracer & Checker HTTP Status Code Checker CIDR / Subnet Calculator IP Range / CIDR Converter MAC Address Lookup

Security Online TLS Scanner Security Headers Checker Email Header Analyzer IP Reputation Checker CT Log Search JWT Decoder

Generators Password Generator Hash Generator SPF Record Generator DMARC Record Generator Content Security Policy (CSP) Generator / Builder

Testers Regex Tester JSON Formatter robots.txt Tester SPF / DKIM / DMARC Checker

Converters Base64 Encoder & Decoder URL Encoder / Decoder Unix Timestamp Converter MIME Type Checker Text Encoding Detector

DNS Admin Course

11 lessons, hands-on labs included — DNSSEC and email authentication taught as one connected system.

Latest NODA Checks

Live dual-axis DNS scores from noda.marinadns.io — updated as checks run.

az-ix.net

Sep 21, 2026 · 06:58 UTC

Health84

Best Practice84

de-cix.net

Sep 21, 2026 · 06:57 UTC

Health98

Best Practice90

namecheap.com

Sep 19, 2026 · 22:42 UTC

Health98

Best Practice92

gtc.az

Sep 19, 2026 · 13:24 UTC

Health97

Best Practice71

designbureau.az

Sep 19, 2026 · 13:05 UTC

Health97

Best Practice71

postmaster.ua

Sep 18, 2026 · 16:42 UTC

Health36

Best Practice50

film.ua

Sep 18, 2026 · 16:42 UTC

Health98

Best Practice87

gnmventures.com

Sep 16, 2026 · 15:56 UTC

Health91

Best Practice86

onsecureserver.net

Sep 16, 2026 · 11:12 UTC

Health92

Best Practice82

Check your domain →

Knowledge base picks

DNS Records & Domain LookupsDNS Lookup, Reverse DNS, WHOIS, and ASN Lookup — what each one shows and how to read it.

DNS Propagation, Health & Blacklist ChecksDNS Propagation, Health Check, DNSSEC, and Blacklist Check — is this domain actually healthy?

Email Authentication — SPF, DKIM, DMARC & HeadersMail Auth Check, SPF and DMARC Builders, Email Header Analyzer — how SPF, DKIM, and DMARC work together.

SSL/TLS Certificates & CT Log SearchSSL Certificate, TLS Scanner, and CT Log Search — certificates, protocols, and issuance history.

HTTP Headers, Status Codes, Redirects & robots.txtHTTP Headers, Security Headers, CSP Builder, Status, Redirects, and robots.txt — one page each.

Guides

Why Is My Email Landing in Spam? A Real SPF, DKIM, and DMARC Debugging WalkthroughA step-by-step investigation into why legitimate mail gets rejected — reading Authentication-Results headers, DMARC alignment, and the fixes in the order that actually works.

NXDOMAIN, SERVFAIL, REFUSED: What Your DNS Error Actually MeansThree DNS error codes get treated as one generic failure. Each one actually tells you who broke and where — read correctly, it narrows the problem before you touch a config file.

How to Read a DMARC Report Without Losing Your MindGzipped XML nobody opens, from providers you've never heard of. Here's what's actually inside a DMARC aggregate report and how to get a real answer in about ten minutes.

DNS Propagation Doesn't Exist (And What's Actually Happening Instead)The 24-48 hour rule is folklore. What's really happening is caches expiring on independent timers — once you see that, the timing becomes predictable and controllable.

Your Certificate Renewed, So Why Is the Browser Still Angry?The file on disk is correct. The problem lives in the gap between the certificate you installed and what a client actually receives and validates.

More guides →