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
