The scenario
Laptop (10.0.1.10) is on the office switch with the Router (10.0.1.1). The Router connects over 10.0.2.0/24 to a Firewall (10.0.2.2), and the Firewall connects to the server switch (10.0.3.1) where Web Server (10.0.3.50) listens on TCP ports 80 and 443. The Router has a static route to 10.0.3.0/24 via the Firewall, and the Firewall has a default route back via the Router; OSPF is switched off on both, and those routes are correct. The cabling is correct too. Exactly three settings are wrong, each on a different device. The goal is plain HTTP from Laptop to Web Server on port 80.
What you will work out
Practise systematic troubleshooting: test, read where and why the trace stops, fix that one thing, and re-test until the whole conversation works.
Why this matters
Real outages are rarely one clean fault; a new server, a firewall change and a mistyped gateway can pile up, and each hides the next. The habit this lab builds is the one that finds them: test the conversation that matters, read where it stops, fix only that, and test again. Checking ping before the application separates routing problems from port and service problems.
Running it
Troubleshooter Challenge: Find Three Bugs opens on a canvas, already wired and addressed. Trace a packet through it hop by hop, or run the same topology live on real Linux network namespaces. How the two modes differ.
Open Troubleshooter Challenge: Find Three Bugs
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