[[router R1]] image = c7200.bin serial0 = "R2 serial0" This tells Dynamips to create a direct serial cable between the two virtual devices on boot. A common mistake is logging into the router and typing:
A: Because IOU/IOL images are binary-level simulations that run natively on Linux. They do not use the Dynamips virtual device layer. They treat serial interfaces as internal software constructs, not hardware emulations. Conclusion: A Feature, Not a Bug The message "Virtual device serial0 will start disconnected" is the emulator's honest way of telling you, "I have no information about what this port should connect to, so I am leaving it in a safe, disconnected state." virtual device serial0 will start disconnected
In a real Cisco router, Serial interfaces use . If no cable is plugged in, the interface remains "down/down." However, emulators are not real circuits. If an emulator tried to auto-detect every possible connection at boot, it would slow down the entire lab startup process. [[router R1]] image = c7200