DNS Diagnostics
20 tools
Propagation checks, record lookups, DNSSEC validation, and ownership context for domain operations.
Infrastructure Diagnostics Hub
One brand hub for DNS, email, network, security, and webmaster diagnostics.
DNSnexus centralizes tool execution, educational guidance, and shareable result URLs so teams can debug faster without account friction.
Live Tools
60+
Across DNS, Email, Network, Security, Webmaster, and IP.
Categories
6
Dedicated hubs with internal linking and structured page architecture.
Result URLs
Shareable
Tool states sync to query params for faster team handoff.
Access
Free
No account required to run diagnostics and read documentation.
Universal Tool Finder
Suggested by intent
DNS incident
Check authority, lookup answers, and propagation.
Email auth
Validate SPF, DKIM, DMARC, and compliance readiness.
Category Command Grid
Jump directly into every tool family.
Each category page groups focused tools so operators can move from broad checks to specific root-cause validation.
Email Authentication & Deliverability
14 tools
SPF, DKIM, DMARC, MX, SMTP, compliance, and reporting checks for sender trust.
Network Operations
7 tools
Route, ownership, address planning, and path diagnostics for infrastructure troubleshooting.
Webmaster & Technical SEO
6 tools
Header inspection, redirects, crawlability signals, and link structure analysis.
Security Checks
8 tools
TLS, DNS, email, and website posture checks with guided hardening workflows.
IP Intelligence
5 tools
Quick geolocation and network ownership context for incident and abuse triage.
Cornerstone Guides
Educational playbooks that pair with live tools.
Guides explain implementation choices, failure modes, and verification strategy for recurring infra tasks.
🌐dns
How DNS Propagation Works: TTL, Resolvers & the Global Timeline
When you update a DNS record — whether you're pointing a domain to a new server, switching providers, or adding an MX record — you won't see the change everywhere at once. Understanding how DNS propagation works is essential for anyone managing infrastructure, because the "24–48 hours" answer most guides repeat tells you nothing useful. The real timeline depends on TTL values you set days earlier, the behaviour of resolvers across dozens of independent networks, and factors entirely outside your control. This guide breaks down the actual mechanism: the hierarchy, the caching chain, resolver-specific behaviour, and the downstream effects on email, SSL, and CDN delivery.
14 minRead guide →
📧email
SPF Record Explained: Setup, Syntax, and the 10-Lookup Limit
When an email arrives claiming to be from your domain, the receiving mail server has no built-in way to verify that claim is legitimate — unless you've published an SPF record. An **SPF record explained** simply is a DNS TXT record that tells the world which servers are authorised to send email on your behalf. Without one, anyone can forge your domain in the From address and receiving servers have no mechanism to detect it. With SPF misconfigured — specifically by exceeding the 10-lookup limit or using the wrong qualifier — your legitimate mail fails authentication just as reliably as a spammer's forged message would. This guide covers everything from the mechanism to the syntax to the traps that catch experienced sysadmins.
9 minRead guide →
📍ip
ASN Lookup Explained: What Autonomous System Numbers Tell You
When you look at a traceroute hop, investigate a suspicious IP address, or try to understand why traffic is routing through an unexpected country, a single piece of information cuts through the noise faster than anything else: the Autonomous System Number. An **ASN lookup** tells you which network operator owns the IP address in question — whether that's a major cloud provider, a regional ISP, a university, a CDN, or a hosting company operating out of a specific jurisdiction. This guide explains what autonomous system numbers are, how BGP uses them to route traffic across the internet, and how to use ASN lookups effectively in real diagnostic and triage workflows.
7 minRead guide →
FAQ
Platform Questions, Answered
This section is intentionally open and fully rendered so users and crawlers can read the complete context.
Frequently Asked Questions
What is DNSnexus designed for?
DNSnexus is a multi-category diagnostics hub for DNS, email authentication, network operations, webmaster checks, and security verification workflows.
Do I need an account to run the tools?
No. Core tooling is available without signup so teams can run checks quickly during migrations, incidents, and routine audits.
How many tool categories are available?
The platform currently covers six categories: DNS, Email, Network, Webmaster, Security, and IP intelligence.
Are tool results shareable with my team?
Yes. Most tools sync key state into URL query params, allowing responders to open the same context during incident handoffs.
How should I use guides with tools?
Use guides for planning and interpretation, then run the linked tools to validate live environment behavior and confirm remediation.
Can browser-based checks replace provider logs?
Browser-safe checks are high-value for triage, but provider logs and authoritative infrastructure telemetry remain the final source of truth.
What makes the homepage different after this revamp?
The homepage now acts as a command center with workflow-driven discovery, category-level navigation, guide pathways, and SEO-first information architecture.
Does DNSnexus support technical SEO troubleshooting?
Yes. Webmaster tools include redirect tracing, header inspection, user-agent checks, link analysis, and technical search presence diagnostics.
How often are new tools and guides added?
The platform is being expanded continuously across all categories, with new tool routes and related editorial guides published in phased batches.
Is this homepage content crawlable by search engines?
Yes. Core sections, guide summaries, and FAQ content are prerendered HTML and fully indexable by search engines.
Next action
Move from discovery to execution in one click
Start with the directory, jump into a workflow path, or open guide-driven diagnostics based on your current operational objective.