The scenario
PC-A (192.168.1.10/24) and PC-B (192.168.1.20/24) are joined by one cable from eth0 to eth0. There is no switch, no router and no default gateway. Both addresses sit in 192.168.1.0/24, so each PC treats the other as a direct neighbour. Everything larger, from an office LAN to the internet, is built from links like this one.
What you will work out
Understand what two devices need to talk over a single link: a cable, and addresses on the same subnet.
Why this matters
Every conversation on a network is carried link by link, and every link needs the same two things this lab shows: a physical connection and matching addressing at each end. Engineers still cable two machines directly to rule out the switch while troubleshooting, or to copy data between them quickly.
Running it
Direct Connection: Two Hosts, One Cable 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 Direct Connection: Two Hosts, One Cable
Runs in your browser. No install, no signup, and the simulation starts instantly.
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