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I had the need to configure a new Cisco 3750 switch at a remote site with minimal hands-on help. I had remote ssh access to an R80.20 3100 appliance on site and wondered if could use the 3750 console cable plugged into the 3100 to access the 3750 switch console.
I arranged for the mini-USB end of the 3750 console cable to be plugged into the Cisco 3750 mini-USB console port and the other end to be plugged into the Checkpoint 3100 appliance Type-A USB port.
Running the dmesg command in expert mode I could see that the GAIA kernel had created a serial device file after the cable was connected:
[Expert@sta-fw01:0]# dmesg | tail -30
usb 1-1.2: new full speed USB device using ehci_hcd and address 3 usb 1-1.2: configuration #1 chosen from 1 choice drivers/usb/class/cdc-acm.c: This device cannot do calls on its own. It is no modem. cdc_acm 1-1.2:1.0: ttyACM0: USB ACM device usbcore: registered new driver cdc_acm drivers/usb/class/cdc-acm.c: v0.25:USB Abstract Control Model driver for USB modems and ISDN adapters
Using the cat command I could see that I had good serial connectivity to the switch:
[Expert@sta-fw01:0]# cat < /dev/ttyACM0 Apr 3 01:26:06.726: %USB_CON
Switch>
Now I just needed to find a terminal emulation program in GAIA that would give me an interactive connection over the serial port to the switch. I searched for tip, minicom and several others to no avail, and then I discovered that GAIA comes with the picocom terminal emulation program installed.
I just ran the command: picocom /dev/ttyACM0 and bingo I had an interactive connection over the USB serial cable to the switch:
[Expert@sta-fw01:0]# picocom /dev/ttyACM0 picocom v2.1 port is : /dev/ttyACM0 flowcontrol : none baudrate is : 9600 parity is : none databits are : 8 stopbits are : 1 escape is : C-a local echo is : no noinit is : no noreset is : no nolock is : no send_cmd is : sz -vv receive_cmd is : rz -vv -E imap is : omap is : emap is : crcrlf,delbs, Type [C-a] [C-h] to see available commands Terminal ready Apr 3 01:42:26.784: %LINK-3-U Switch>
Switch> en
Switch#
Switch# show ver | inc Cisco
Cisco IOS Software, C3750E Software (C3750E-UNIVERSALK9-M), Version 15.2(1)E2, RELEASE SOFTWARE (fc1)
...
...
...
Switch#
Once connected via picocom, Ctrl-a Ctrl-h displays a helpful list of escape sequences like Ctrl-a Ctrl-x to end the session:
*** Picocom commands (all prefixed by [C-a]) *** [C-x] : Exit picocom *** [C-q] : Exit without reseting serial port *** [C-b] : Set baudrate *** [C-u] : Increase baudrate (baud-up) *** [C-d] : Decrease baudrate (baud-down) *** [C-i] : Change number of databits *** [C-j] : Change number of stopbits *** [C-f] : Change flow-control mode *** [C-y] : Change parity mode *** [C-p] : Pulse DTR *** [C-t] : Toggle DTR *** [C-|] : Send break *** [C-c] : Toggle local echo *** [C-s] : Send file *** [C-r] : Receive file *** [C-v] : Show port settings
Anyways, I thought others may find this helpful for remote configuration of devices with a USB console port in a pinch.
The same method could be used to remotely configure a Checkpoint Appliance manually using isomorphic USB GAIA installation and the config_system command for the first time configuration.
Al
Nice, had no idea that was possible.
This is great! Thank you for sharing.
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