NETWORK INCIDENTS

Learn the commands

Short videos for homelab beginners. Each one takes a single networking command, runs it on a real lab network, and explains every line it prints: what it's for, how to read it, and what it shows you when something is broken.

The commands

$ dig

dig, explained

Ask a DNS server a question and read the whole answer. What NOERROR and NXDOMAIN mean, and what it tells you when no server answers at all.

Watch on YouTubeSee it find a real fault: Ping works, websites don't
On Windows and Mac

Mac

dig web.homelab.testdig @10.0.10.53 web.homelab.test

Open Terminal. dig is usually already installed on a Mac, so the commands in the video work as shown, and the answer reads the same way. Type man dig to see the manual for the version you have.

Windows (Command Prompt or PowerShell)

nslookup web.homelab.testnslookup web.homelab.test 10.0.10.53

nslookup is built into Windows. Give it a name to ask your default DNS server; add a server's address after the name to ask that server instead, like dig's @. When a lookup fails it says why in words: "Nonexistent domain" means the name doesn't exist, which dig shows as NXDOMAIN. "timed out" means the server didn't respond, and "No response from server" means no DNS server is running there: in dig, both end with "no servers could be reached".

Source: nslookup, Microsoft Learn

Windows PowerShell

Resolve-DnsName web.homelab.testResolve-DnsName web.homelab.test -Server 10.0.10.53

Resolve-DnsName does the same job in PowerShell; Microsoft describes it as functionally similar to nslookup. -Server picks which DNS server to ask, like dig's @.

Source: Resolve-DnsName, Microsoft Learn

Coming next:

pingip addr and ip routeip neighcurl -vtcpdump

How to use these

  1. Watch the explainer. Everything on screen is real output from a small lab network, not a mock-up.
  2. Try the command on your own network. Most of them only read information and change nothing.
  3. Then watch it solve a real problem: each explainer links to an incident episode where the command found the fault.
  4. Want the same lab on your computer? See Run the labs yourself.