VI. Feature Setup


Using the VigorSwitch FX2120 with 1Gb SFP Links

VigorSwitch FX2120
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The DrayTek VigorSwitch FX2120 is a 10 Gigabit on all ports, SFP+ switch. It is designed primarily to be connected to a 10Gb capable switch or router, such as the Vigor 3910 or VigorSwitch G2280x.

If no 10Gb SFP+ cable device is available and the VigorSwitch has firmware of 3.7.2 or earlier, the VigorSwitch FX2120 will not auto-detect the port rate of a lower speed SFP module or DAC. This means that a configuration change must be made on the VigorSwitch FX2120, for network connectivity to operate with a 1GB SFP.

There are two methods to resolve this:


Temporarily connect the VigorSwitch FX2120 to a 10Gb capable SFP+ device using the supplied SFP+ DAC cable.
Access the VigorSwitch FX2120's web interface and reconfigure the Port Speed under the [Configuration] > [Port Setup] menu.
Once the port setting has been changed, the VigorSwitch FX2120 can be connected to a 1Gb SFP on the reconfigured port.


Connect to the VigorSwitch FX2120's Console port with a suitable RS-232 serial port. Then through the console interface, reconfigure the desired SFP port to 1Gb operating speed.
Connect a 1Gb SFP to the reconfigured port to access the Web Interface of the switch.

Method 1 - Reconfigure via Web Interface

Connect up the VigorSwitch FX2120's supplied SFP+ DAC cable to another device's SFP+ port, on a DrayTek router such as the Vigor 3910, or 10Gb capable switches like the VigorSwitch P2280x (x indicates 10Gb capable). With the 10Gb link established between the two 10Gb capable devices, connect a PC up to any of the 1Gb ports on the other device. That will allow the VigorSwitch FX2120 to receive an IP address and be managed from the network.

To quickly locate the VigorSwitch FX2120 on the network, it's recommended to use the [External Devices] menu on a DrayTek router, which will list all DrayTek devices on the same physical network. To use the feature, go to the External Devices menu, ensure that the "External Device Auto Discovery" option is ticked, then click OK if it wasn't already enabled. Once the External Devices functionality is active, the VigorSwitch FX2120 should then be listed. Click the "On Line" link to access the switch:

fx2120 externaldevices

Where a DrayTek Vigor router isn't available, the DrayTek Device Finder can be used to locate the VigorSwitch FX2120 on the network:

fx2120 devicefinder

Both of these options will open the VigorSwitch's IP address in a browser, accessing via HTTPS. This will usually give a certificate error because the certificate is self-signed, allow an exception to access the management interface.
To log in to the switch, use the default username of "admin" and the default password of "admin":

fx2120 setup 3

Once logged in to the VigorSwitch FX2120, expand the side menu bar if it isn't already expanded, by clicking the ≡ icon in the top left. Expand the [Configuration] menu and go to [Port Setup]:

fx2120 wui portsetting1

From the Port Setup menu, click the edit icon for the port that needs to be used at 1Gb speed.

This will expand the Port Setting menu. Click on "Show Advanced Mode" to see the Port Speed settings.

Click on the Port Speed drop down, which may be on "Auto" or "10G" depending on the firmware the switch was supplied with. Select "1000M" Port Speed from the drop down list. Then click OK to save and apply the change.

fx2120 wui portsetting2

With the port speed now changed for that port, the VigorSwitch FX2120 can be disconnected from the 10Gb capable devices and plugged into the 1Gb SFP on the reconfigured port. If a 1Gb link is connected successfully, the LED to the left of the VigorSwitch FX2120's SFP+ port will light up in green to indicate 1Gb speed.

Method 2 - Reconfigure via Console Port

Where a 10Gb device isn't available to connect to the VigorSwitch FX2120 for initial setup, it's possible instead to use the Console port on the VigorSwitch FX2120. This provides access to the switch's Command Line Interface, where the port speed settings can be reconfigured for 1Gb compatibility.

Hardware Requirements:

  • RS-232 DB-9 to RJ-45 adapter/cable - Not supplied with the FX2120, included with Vigor 3910 & other 10Gb capable Vigor Switches
  • Serial (RS-232) Com port on a computer
  • USB to Serial (RS-232) adapter (not supplied)

Software Requirements:

  • Terminal software such as Putty

If the computer does not have an integrated Serial (RS-232) Com port, connect a USB-to-Serial adapter and ensure its drivers are installed. To find the Com port that it’s been assigned on the computer, in Windows open the start menu and type “device manager” to open the Windows Device Manager control panel:

fx2120 devicemgr

In the Device Manager, scroll down to the “Ports (COM & LPT)” section and expand it like so:

fx2120 devicemgr2

In this example, the USB-to-Serial adapter is on Com port 6. Note the Com port number and close the Device Manager.

Connect the Serial port up to the RS-232 to RJ-45 cable, which is then connected into the “Console” port of the VigorSwitch FX2120.

Open Putty and set the Connection type to Serial.
Specify the Serial line as the COM port number shown in Windows Device Manager, in this instance the computer is using COM6.
Set the Speed to 115200, this is the communications baud rate used by the FX2120.
Click the “Open” button to start the serial connection:

fx2120 serialsetup

Upon connection, the switch should display the “Username:” prompt, however if nothing is displayed, press the Enter key and the prompt should then appear. Enter the switch’s standard username of “admin” and the password of “admin”. When connected successfully, the switch will display this prompt:

fx2120 console1

 From there, enter the following commands to change the SFP port speed. The switch uses ports 1-12, with 12 used in this example:

fx2120 console2

In the above example, the “show interfaces 10GigabitEthernet 12” command checks the current port speed setting and whether it’s connected or not.

  • The “interface 10GigabitEthernet 12” command enters the sub-menu for port 12’s interface settings.
  • The “speed 1000” command changes the speed to 1000Mbps rate.
  • The “exit” commands are used to exit the (config) and (config-if) sub-menus.
  • Type “save” to save the new settings on the switch if you’d like that to be the default setting when the switch is next powered up.
  • The “show ip” command displays the FX2120’s current IP address.

In this example, the switch has received an IP address via DHCP and is now on “”. If the switch is unable to receive an IP address via DHCP it will default to “”.

Once the port rate has been changed, connect the switch to a 1Gb SFP with the supplied DAC-CX10 cable or similar. If the link is able to establish, the LED to the left of the SFP port will now glow green. If the link light is now lit green, the “show ip” command through the Console interface can be helpful for locating the switch on the network.

The default IP address of the VigorSwitch FX2120, which will be used where an IP address is not supplied via DHCP, is with a subnet mask of Configure the IP address of the computer to be within the same subnet. For a full demonstration of how to configure an IP address manually, see this guide: https://www.draytek.co.uk/support/guides/kb-windows-fixedip

Logging in to the VigorSwitch FX2120

fx2120 setup 3

Once the VigorSwitch is located on the network, open the VigorSwitch FX2120’s web interface in a web browser. Log in with the default username of “admin” and a default password of “admin”, which is case sensitive.

The switch will then display the Dashboard and can now be configured for use:

fx2120 setup 4