Technical guides for every NetTools.tech tool — what it does, how it works, how to read the results and how to troubleshoot — plus articles for system administrators, DevOps engineers and security professionals.
Tool guideDNS & Domains
How to find out whether your router, firewall or DNS server answers recursive queries for anyone on the internet, what the RA and AA flags mean, and how to close an open resolver.
Category guideDNS & Domains
An overview of the NetTools.tech DNS and domain tools: what each one checks, which to reach for when a domain does not resolve, a change is not visible or a certificate fails, and how to combine them.