Interactive DNS visualizations
Animations to follow sessions 2.1 and 2.2 at your own pace: the DNS told step by step from the why, how zones are delegated and how a query gets resolved, also with the modes you choose. (The animation on the anatomy of a name is only available in Spanish.)
Anatomy of a name: from labels to the tree
Break any name into labels and domains and see it in the tree, from the root or from the name. Check the rules, 63 characters, trailing dot, case and punycode.
Session 2.1Versión en español
DNS zone delegation
Step by step through the IANA → Red.es → UAH → Department chain, with zone files. In "Delegate it yourself" you create domains and hosts and delegate them yourself, with NS records, glue and referrals.
Session 2.1Versión en español
DNS queries: iterative and recursive
Message by message, resolving gaia.cs.umass.edu with an empty cache. Compare the two modes and notice who has to remember other people's queries.
Session 2.1Versión en español
DNS queries: you decide who is recursive
The same resolution, but you choose whether the local server, the root, the TLD and the authoritative server work recursively or iteratively. Compare who sends the queries, who has to wait and where the answer ends up cached.
Session 2.1Versión en español
DNS step by step
The DNS told from the why in 27 steps, from why an IP address is not enough to a query followed message by message. Why we need names, how the tree is split up, what your computer sees and what happens behind it, and where each query is recursive or iterative.
Session 2.2Versión en español