In the event that network connectivity issues prevent conventional access to management network switches, then it is recommended to access them using the serial/COM ports on the management switches.
A USB-DB-9 or USB-RJ-45 cable is connected between the switch and the NCN.
(ncn-mw#) Use minicom, screen, or cu to connect to the switch’s console.
screen
screen /dev/ttyUSB1
screen /dev/ttyUSB1 115200
minicom
minicom -b 9600 -D /dev/ttyUSB1
minicom -b 115200 -D /dev/ttyUSB1
cu
cu -l /dev/ttyUSB1 -s 115200
Some specifics such as BAUDRATE and terminal usage vary per manufacturer.
Refer to the external support/documentation portals for the specific manufacturer (e.g. Aruba, Dell, Mellanox) for more information.
On Mellanox switches, if the console is not responding when opened, try holding CTRL + R (or control + R for macOS) to initiate a screen refresh. This should take 5-10 seconds.
If there is no device in /dev/tty*, then follow dmesg -w and try reseating the USB cable (unplug the end in the NCN, and plug it back in).
Observe the dmesg -w output. Look for errors pertaining to USB. The cable may be bad, or a reboot may be required.