sysop@hub:~/tools/packet-journey$

packet-journey

Somebody types an address and a page appears. In between, twelve things happen, and each one fails in its own way. Walk the request from the PC to the server and watch the packet change. Then break something and see where the journey stops and what the user would tell you on the phone. At the end, ten tickets wait: find the fault from the symptoms.

guess the fault

Ten tickets. You get what the user reports and one check. Run more checks if you need them, then say what is broken.

A model with one PC, one switch, one router and a server: real networks have more of each, the stations stay the same. Addresses are placeholders, the timings and hop counts are typical values, and the browser error texts are those of Chromium. Go deeper with the networking cheat sheet, the DNS walkthrough, the DHCP walkthrough, the firewall rule reviewer, the certificate decoder, the subnet calculator and the network wizard. Draw your own path with the network diagram builder.