The Cisco Catalyst 2950 switch is malfunctioning.
The Cisco Catalyst 2950 switch is malfunctioning.
You received a second-hand Cisco Catalyst 2950 switch that initially functioned but later lost connectivity. Attempts with PuTTY using default settings failed, though Device Manager shows an unknown device. No driver was found. Consider checking physical connections, updating firmware, or testing the switch via serial console on your Windows Server 2012 R2 using a Cisco serial-to-RJ45 adapter.
Initially there’s always the nuclear choice of defaulting. For your serial problem, if you lack drivers for your built-in serial port, you can use a USB serial adapter. At our workplace we’ve discovered the Chipi-X brand to be the most dependable (our project needs several hundred units constantly, so investing a bit more makes sense). I haven’t run into issues with Startech or monoprice products. Most USB to serial adapters work seamlessly in Windows and Linux since there are only a few key chipsets. The default serial settings in putty usually function well, but many devices advise setting flow control to none. Clearly, you need the correct COM port number for each device manager. If defaults fail, consider using a baud rate of 115200 instead of 9600—this is typical when uploading new firmware because it speeds up transfers and prevents delays.
I'll attempt the USB method I believe we have, and I noted flow was disabled.