We have a Vigor 2927ac connected via Virgin Fibre (1Gbps) and want to use our old Vigor 2862ac (connected to PlusNet VDSL) as WAN2 failover.

The 2862 was the main router and PlusNet the main supplier (failing over to 4G). Once the Virgin Fibre was installed, set it up on WAN2 as the primary connection, with WAN1 (PlusNet VDSL) as first failover and 4G as second failover on WAN3. This works fine... except the 2862 has a 400Mbps limitation on NAT, so speeds were being throttled. There is currently no VDSL capable router available without that NAT speed limitation (looks like there is 2865 planned but not available yet?) so we went for the 2927.

The 2927 works perfectly with WAN1 connected to the 1Gbps Virgin Fibre (achieving full speed) using the 4G as failover on WAN3.

However, we are unable to get the WAN2 port to connect via the 2862 (and its VDSL connection).

Connection and setting details:
With the 2927 working fine on WAN1 and the separate 2862 working fine on WAN1 VDSL, we changed the 2862 WAN1 Internet Access "PPPoE Pass-through" setting by ticking the box "For Wired LAN", clicked OK and allowed the router to reboot. WAN2 Internet Access settings on the 2927 were changed to enable PPPoE and the PlusNet username and password were added (same as on the 2862). The 2927 was then also rebooted.

The 2927 WAN2 port was then connected to the 2862 LAN Port 1 and the 2927 WAN1 disconnected to force a failover. The 2927 tried but was unable to establish an internet connection.

Can somebody please advise what we are doing wrong? Is there a different way to achieve our goal?

Also, as a side note, how can the 2862 "PPPoE Pass-through" setting be changed back, since it is no longer possible to connect to the management page as it doesn't have an IP? The only way we have managed to achieve this, is to factory reset and restore from backup.

Thank you for taking the time to read this, and any help is genuinely appreciated.

Someone claimed to have something similar working here: https://community.ui.com/questions/USG-with-Draytek-Vigor-2860-in-Bridge-Mode/5c9cd3da-7b17-4c95-ae55-dd1642d51ede

In that forum, Arthur Mitchell wrote: I thought I'd share my experience of getting a Draytek Vigor 2862 working just as a modem with a USG. This took a full day to figure out as the easy and obvious selection on the PPPoE tab that is marked as "PPPoE pass through" doesn't seem to work as suggested in the footer text.

The only way to estabish a PPPoE link from the USG is to disable both PPPoE and ATM bridge tabs leaving only the base VDSL setup page active. This is the one containing the VLAN tag. Leave the VLAN tag as 101 (for BT in the UK).

This allows the Draytek to start the VDSL connection but prevents it doing anything else, since if it starts up and PPPoE login this stops the USG getting in on the connection.

The USG can the be configured for PPPoE with the user name and password but you need to leave the VLAN tag unchecked. So far this is working just fine.

To contine to access the Draytek to view the line parameters and status I turned off the DHCP server on the LAN page and fixed to IP to a valid 10.x.x.x address for the new network.

TwoSuits wrote:
Also, as a side note, how can the 2862 "PPPoE Pass-through" setting be changed back, since it is no longer possible to connect to the management page as it doesn't have an IP? The only way we have managed to achieve this, is to factory reset and restore from backup.

"Arthur Mitchell" suggests one method (presumably you'd need a matching 10.x.x.x address on the 2927 WAN2)...other suggestions are to leave the WiFi 'unbridged' and access it that way.

Thanks very much for the reply. It's good to know I am not the only one that has had issues.

I will try these suggestions next time I am at that site (which may well be several weeks) and post back here once I have a definitive solution.

Sounds like you've gone down exactly the same route as I have, but with different ISPs!

Setting up the 'PPPoE Pass-through' on the 2862 is not very intuitive! On your 2862 go to the WAN/Internet access page and set the WAN1 access mode to 'None'. If you don't do this, then the 2862 will still try to connect to your ISP, even though you've got 'PPPoE Pass-Through' enabled. If the 2862 is connected to your VDSL ISP then your 2927 will not be able to make a connection.

Once you set WAN1 access mode to 'None', the 'Details Page' button greys out - even though you may still need access to the 'Details Page'. To work around this, just click on the WAN1 IPv6 button instead, and then click on the PPPoE/PPPoA tab to get to the setup page. On this page, make sure PPPoE/PPPoA is disabled (this doesn't disable the modem), and ensure PPPoE Pass-through is enabled.

Once you've done that your 2927 should be able to make a connection to your VDSL ISP.

Your 2862 should still have an IP address and should still be accessible. I currently have 2 connections going into the 2862. One of these is from the WAN2 port of my 2927, and the other is from a LAN port of my 2927. The connection from the LAN port of my 2927 is what allows me to still communicate with and configure the 2862. I don't think it matters which ports you use on the 2862. Currently I have 2927 WAN2 connected to 2862 Port 6, and 2862 Port 1 connected to my LAN.

Edit: I notice that there is now a Vigor2865 available, which is probably the device we were looking for - instead of the 2927!