Dns guides
Hands-on guides that cover Dns. Every command is run and verified on a live server before it is published.
GuideHow DNS Resolution Works
Install bind9 and unbound on a bare Ubuntu 24.04 slice, then read DNS resolution: authoritative versus recursive servers, dig +trace and the common record types.
GuideRun an Authoritative DNS Server with BIND9
Run an authoritative DNS server with BIND9 on Ubuntu 24.04: a real boxlab.space zone file, named-checkconf and named-checkzone, and answers with the aa flag.
GuideDNS Resolution
Understand linux dns resolution: how a name becomes an IP address on Ubuntu, how to query a name with resolvectl, and how to read where the answer came from.
GuideA Recursive DNS Resolver with Caching
Build a recursive DNS resolver with unbound on Ubuntu 24.04: validating caching on 127.0.0.1, a cold versus warm query proving the cache, forwarding and prefetch.
GuideSplit-Horizon DNS for Internal Names
Set up split-horizon DNS with BIND9 views on Ubuntu 24.04: one name answers a private address to internal clients and a public address to everyone else.
GuideDNSSEC and DNS Troubleshooting
Sign a zone with DNSSEC on Ubuntu 24.04 and read the DNSKEY, RRSIG and DS records, validate the ad flag, then troubleshoot SERVFAIL, NXDOMAIN and a broken record.