Occasionally, a support inquiry requires the customer to access his unit via serial cable/console cable in order to reach the command-line interface (CLI). The CLI sometimes offers special debug commands, which are not accessible over the normal web interface. In this tutorial, we want to show you how to get that going, what cable we in our office use and give you some hints around this topic.
Which cable to use?
Most of our devices' console ports use an RS232 port (Sub-D, 9-Pin, Female), so our recommendation would be some sort of RS232 (Sub-D, 9-Pin male) to USB cable, as depicted below:
However, some of our units come with RJ45-Ethernet-sized console ports (such as the smaller USG20/40-series).
In that case, the Console cable should be within the packaging content, consisting of a blue cable with both RS232 to Ethernet plugs.
Note: The RS232 plug is a female Sub-D 9-Pin-plug and requires a fitting serial cable port on your PC/Laptop! If your device does not provide such port, we recommend getting the cable with "Sub-D 9-Pin male to USB" as depicted above in addition, to get the proprietary console cable connected to your PC.
What program to use?
There are a multitude of different programs to use - however, we recommend to use what has become the market standards: either TeraTerm (https://osdn.net/projects/ttssh2/releases/) or PuTTY (https://www.putty.org/).
Due to the fact that PuTTY is primarily used rather as an SSH-client we will focus in this tutorial on how to use TeraTerm.
- Connect the console cable between your Zyxel unit and your PC/Laptop
- Start TeraTerm. You will be prompted to select your input source. Select the "Serial"-bullet and select the respective port from the dropdown menu, then click "OK"
- Then press any button (most likely "Enter"-button) to trigger the program to connect and display the console login menu.
- If everything is set up correctly, you should now be able to enter your user credentials:
If you see cryptic messages or eventually the screen stays black (empty), it might be that the serial port is not set up correctly - in that case, please navigate to "Setup > Serial Port":
In most cases, the baud rate is not set properly - most of our Firewalls and Access Points work by default via 115200 bd/s, most of our switches work with 9600bd/s:
Change to the respective value. If you are unsure, please check the user guide of the device for more information.
If you follow these instructions, you should be able to access your device via console terminal - congratulations! For any further support needed on this, please do not hesitate to contact our support directly.