Using the Vigor 166 as a DSL modem

The Vigor 166 modem is able to connect to G.fast, VDSL and ADSL2+, but the out-of-the-box configuration is specifically intended to pass through G.fast and VDSL connections, which use PPPoE (PPP over Ethernet) and direct IP connections, along with streaming services.

Connecting DSL with the Vigor 166 requires some reconfiguration, in that it needs to use Router Mode and PPPoE Pass-Through to convert PPPoE connections from your router or firewall, to the PPPoA (PPP over ATM) used by ADSL ISPs in the UK.

Accessing the Vigor 166 Web Interface

Out of the box, the Vigor 166 modem does not have DHCP enabled to automatically configure client IP addresses. This is a requirement of the fully bridging VDSL/G.fast functionality, but it can complicate accessing the web interface without automatic IP assignment.

To start reconfiguring the Vigor 166 modem, connect a PC to the Vigor 166's LAN port (either P1 or P2), configure its IP manually to an address in the 192.168.2.x range and access the Vigor 166 modem on http://192.168.2.1.

To do that in Windows 10, go to the Settings menu and select Network & Internet:

In the Network & Internet > Status menu, click on the Properties button for Ethernet:

Scroll down to the IP settings section and click Edit to change the IP assignment from "Automatic (DHCP)" to a fixed address:

In the Edit IP Settings menu, enter these settings:

IP Assignment mode	Manual
IPv4	On
IP address	192.168.2.100 Or any address in the 192.168.2.x range, but not 192.168.2.1
Subnet prefix length	24
Gateway	This can be left blank if this is just for modem setup, otherwise set 192.168.2.1
Preferred DNS	This can be left blank if this is just for modem setup, otherwise set 192.168.2.1

Click Save to save and apply the new IP settings.

Now, the IP address setting for the Ethernet adapter should look like this. Once the IP address is set, the Vigor 166 modem should be accessible.

Open a web browser on the computer and go to http://192.168.2.1, then enter the username/password at the login prompt. Alternatively, use HTTPS, which is more secure but will give a self-signed certificate error if you haven't accessed the web interface previously with HTTPS. Select "Continue to the webpage" if you see a certificate error message.

The Vigor 166's default username and password are "admin":

If the password has not been changed from its default setting, this message will be displayed. Click OK to proceed. You can set the password from the [System Maintenance] > [Administrator Password] menu.

Changing the Vigor 166 Operation Mode

Now go to [Operation Mode]. If this menu option isn't available, update the Vigor 166 to the latest firmware.

Select Router Mode as the Operation Mode, then click Next:

This starts a brief setup wizard for the Router Mode, to quickly configure some important settings for the Vigor 166 to operate in Router Mode.

Click Next for these settings.

Optionally, you can select ADSL as the DSL Mode. This may reduce sync times but will not be able to connect to VDSL or G.fast if the line is changed, unless the DSL mode is changed again.

In the next step of the router mode setup wizard check that these settings are correct for the UK, the ADSL settings should be:

• Encapsulation: PPPoA VC MUX
• VPI: 0
• VCI: 38

The other settings can be ignored, click Next to continue.

The IP address can be reconfigured here if needed.

If you intend to use the Vigor 166 as a router, it may help to set the DHCP Server setting to Enable, otherwise click Next

On the settings summary screen, click Apply & Reboot:

Now wait until the Vigor 166 has rebooted with the new settings. There should be an audible 'click' when the modem has finished restarting.

Enable PPPoE Pass-Through

Back in the Vigor 166 web interface, the menu layout has changed to the Router Mode layout, with options available for operation as a NAT router.

It can still be used as a modem in this state, with PPPoE Passthrough enabled in the next steps:

Go to [Internet Access] > [PPPoE / PPPoA] and check the settings. They should show the PPPoE/PPPoA Client as Enabled.

PPPoE Pass-through may already be enabled for wired LAN clients. If it's not enabled, enable the checkbox and click OK to save and apply the change.

With PPPoE Pass-through enabled on the Vigor 166 modem, it will now be possible to establish a PPPoE connection from the connected router / firewall, once the ADSL connection has established.

Check ADSL connection status from the [Online Status] > [Physical Connection] screen:

 The connection can now be used with an Ethernet router or firewall. The computer can be disconnected, and its IP address assignment can be reconfigured to use Automatic (DHCP).