Articles
The tools on this site show you what is happening. These explain why it happens that way.
DNS and domains
The hierarchy behind every domain name β the root zone, top-level domains, delegation and glue, who runs what, and how whois and RDAP find the right server to ask.
Answers questions like
- Are there really only 13 root servers?
- Where is the dot at the end of a domain name?
- How does a resolver know which server to ask?
Routing and ASNs
Why there is no centre, what an AS number is for, how a packet finds its way, where IP addresses come from and what they cost β and what it actually takes to become your own network.
Answers questions like
- Who owns the internet?
- What is an autonomous system number for?
- Why is the autonomous system more reliable than the country in an IP lookup?
Bots in your logs with ready-made lists
What the search, AI, preview and SEO bots in your logs actually do β where each operator publishes the addresses its crawler uses, how to verify one yourself, and a ready list of verified ranges to download.
Answers questions like
- Can I just block by User-Agent?
- How do I verify a crawler by IP address?
- Why is checking the ASN not good enough?