Use Connection Builder to choose two devices and a free interface at each end. Swap the device selections, then close the builder without making a connection. Create a cable and see that its occupied ports no longer appear in the free-interface lists. Review the disconnection confirmation, cancel to keep the cable, then confirm its removal. Reconnect using a different free port on each device, and reopen the lab to check the saved connection. This walkthrough uses two simulated routers. Cabling alone does not configure device addressing. Configure interface addressing and interface state separately before testing traffic.
