Asr-9xx-usbconsole-drivers ✯

For macOS 10.14 and earlier, the .pkg installer works. For macOS 11+ (Big Sur and later), the driver is broken due to kext deprecation. Workaround: Use a standard RJ-45 console cable with a USB-serial adapter instead.

The keyword asr-9xx-usbconsole-drivers refers to a set of official Cisco driver files—available for Windows, macOS, and Linux—that enable a host computer to recognize and communicate with the USB console port on an ASR 9000 series router. asr-9xx-usbconsole-drivers

Then use screen /dev/ttyACM0 9600 .