DomScan
Guides, product updates, domain research, DNS explainers, and technical breakdowns from DomScan.
TXT records started as a place for human-readable notes in DNS. They now carry the machine-critical data that decides whether your email arrives, your domain is verified, and your security policies are enforced.
A records map hostnames to IP addresses. CNAMEs alias one hostname to another. The choice between them determines how CDN routing, SSL issuance, email delivery, and DNS migrations actually behave in production.
NS records are the delegation chain of DNS. Get them wrong and your entire domain goes dark. Here is how to check, diagnose, and fix nameserver configuration problems before they become outages.
When you send an email, your mail server queries MX records to find which servers accept mail for the destination domain. This guide explains MX priority, fallback chains, common configurations, security implications, and troubleshooting.
DNS server means different things depending on context. This guide breaks down the four types, compares public resolvers, walks through configuration on every major OS, and covers troubleshooting and security.
A DNS leak exposes every domain you visit to your ISP, even when you think a VPN or encrypted resolver is protecting you. Learn what causes DNS leaks, how to test for them, and how to fix them permanently.
An IP address lookup returns three distinct categories of data: where the address is located, who operates the network, and who to contact when something goes wrong. Each has different accuracy levels and different operational uses.
A DNS checker queries multiple resolvers worldwide to reveal whether your DNS changes have propagated and whether your records are consistent. Learn how to verify DNS records systematically instead of guessing.
An IP lookup reveals geolocation, ISP, ASN, organization, and abuse contacts for any address. This guide explains how geolocation databases work, what accuracy you can actually expect, and how to run a proper IP investigation workflow.
Every URL you visit starts with a DNS lookup that finishes in under 100 milliseconds. This guide walks through the full resolution chain, record types, caching, common errors, and security signals.
Domain valuation is part language, part market context, and part buyer fit. This guide explains what actually drives domain value and how to interpret automated appraisals realistically.
Bulk WHOIS work is less about sending thousands of queries than about turning inconsistent registration data into something you can actually analyse. This guide explains how to do that well.
Domains are not static registration entries. They are operating surfaces for DNS, certificates, mail, web traffic, and brand trust. This guide explains how to monitor them like real production assets.
Domain loss is usually an ownership and process failure long before it becomes a registrar-date problem. This guide explains how to monitor critical domains so they do not quietly slide toward lapse.
Cybersquatting is a legal and operational problem. This guide explains what actually counts as cybersquatting, when UDRP is the right path, and how to prepare stronger recovery evidence.
Domain reputation is the accumulated trust judgment attached to your domain identity. This guide explains what feeds it, how it degrades, and what operators can do to improve it without chasing myths.
Attack surface management is the work of turning forgotten internet-facing assets into observable, owned, and prioritised risk. This guide explains how domain-led discovery makes that possible.
Typosquatting is a trust-abuse problem disguised as a naming problem. This guide explains how attackers use typo variants, why they matter operationally, and how defenders can reduce the risk.
Wildcard and multi-domain certificates solve different trust-scope problems. This guide explains the coverage, operational tradeoffs, and blast-radius implications behind each model.
Certificate monitoring should cover trust drift, deployment mistakes, and unexpected issuance, not only one date on a calendar. This guide explains how to build a monitoring routine that prevents outages.
Browsers trust chains, not isolated leaf certificates. This guide explains roots, intermediates, and why certificate trust fails in production even when a certificate looks “valid.”
Current DNS gives you a snapshot. Historical DNS gives you a timeline. This guide explains how to use record history for incident response, threat hunting, and domain investigations.
Reverse DNS is more than a curiosity in a mail header. This guide explains how PTR records work, why reverse lookups matter for mail and investigations, and where teams misread them.
DNS propagation is not one global timer. It is the practical effect of caches, TTLs, resolver behaviour, and where the change was made. This guide explains what actually determines visibility after a DNS update.
DNS records are easy to define and much harder to operate well together. This guide explains the major record types, what question each one answers, and where teams create avoidable confusion.
Business email security sits at the intersection of domain identity, workflow trust, and brand protection. This guide explains how to build controls that reduce spoofing, impersonation, and payment-risk exposure.
SPF becomes fragile when it turns into a dumping ground for vendors. This guide explains how to keep sender authorization records within limits and maintainable as the mail stack grows.
Deliverability is easier when domain identity is boringly coherent. This guide explains how SPF, DKIM, and DMARC influence receiver trust and why weak authentication makes inbox placement harder.
DMARC reports are useful only when they become operational decisions. This guide explains what aggregate reports actually show, how to triage them, and how to use them for policy rollout.
SPF, DKIM, and DMARC are not separate checkboxes. They form one operating system for mail identity, authorization, and policy. This guide explains how the stack works and how to deploy it safely.