Fibre Network failover to ADSL


New Member
May 30, 2016
I have recently installed FTTH with TT CONNECT with Fredd as service provider and we are down once or twice a week. I still have ADSL with a different service provider. I have kept both until there is stability in the area as there are still large installations going on in the area. I have a small business from home and run a server with a few PC's through a network. I physically reconnect between the 2 routers when the fibre has downtime. But looking for a solution that there is a failover without having to physically disconnect the Fibre to connect to the ADSL router. Any suggestions


Expert Member
May 2, 2007
For DSL I would normally run the PPPoE sessions from the server, setup for "Internet Comnection Sharing" (iow NAT and DHCP). Then you should be able to:
- Add another NIC to the server (if it doesn't have an unused port)
- Setup another PPPoE session from it

(I haven't touched a Windows machine in 2 years, and haven't used Windows server for this use case since Windows server 2003 , but doing it on Linux would be easy).

If your FTTH provider doesn't use PPPoE, then it may be more difficult to get it automated, because the server doesn't automatically know that the comnection is down like it would with the PPP connection being terminated.


Well-Known Member
Sep 10, 2018
You can manual-switch between networks from your desktops.
Without moving any cables.

Assuming you're referring to cabled connections all round?. (not wifi)
Assuming you're referring to normal "dumb" Fibre/DSL routers that have 4 x switch ports built-in.

Connect your fibre and DSL routers to one another.
Run an Ethernet cable form one of the fibre router's switch ports to one of the DSL routers' switch ports. (any one of the usual 4)

You (and 2? other PC's) remain connected to the fibre router..
While fibre is up, you all connect through the fibre router's WAN port (fibre cable).
pc -> fibre router ethernet port -> fibre router WAN port -> fibre

When the fibre connection falls over, change your computers IP address details and you'll be connected over DSL (through the fibre router's switch port)
pc -> fibre router ethernet port -> DSL router ethernet port -> DSL router WAN port -> DSL

This ONLY works if you remember to change the IP address details on your PC's to point to the DSL default gateway.

Fibre LAN is on 192.168.1.X/24
DSL LAN is on 192.168.0.X/24

You can setup (Google?) a batch file on your desktop for easily (double-click) changing from the 192.168.1.X subnet to the 192.168.0.X subnet and another batch for changing back.

It's a bit of a "hack" but it works PLUS it saves you from getting up from your chair and disconnecting/reconnecting cables.


Active Member
Dec 18, 2012
I would say the best way would be to get an ubiquity edgerouter x and set it up for 2 wan loadbalancing. It would use both internet connections simultaneously and you would not even notice if one connection stops working. It can also do failover, so it would use one connection and switch to the other if the primary connection fails. This can also be done cheaper using pfsense on an old pc with multiple network ports.


Honorary Master
Jul 24, 2006
Yay for PfSense. I have failover set up between my fibre and dsl, the only time I notice the fibre going down is when the Youtube videos don't play at 4K.


Senior Member
Dec 27, 2009
I think TP-Link has a load balancer which can act as a failover the model is TL-R470T+ and the TL-R480T+ only issue i see is they only have 100mb lan ports and no wifi. Not sure how well they work maybe if somebody has used them can give pro's and con's???

I have setup a Draytek Vigor router and this thing is the bomb, but they very expensive for a home router, around 5 or 6k I think for the ac wifi one.


Well-Known Member
Mar 22, 2005
I use pfsense as a firewall, you can automatically configure connection sharing as well as fallover connections and weigh your gateways. Works like a charm and you set and forget it. It can run on very old pc's, not very much hardware intensive.


Company Rep
Mar 26, 2018
Quick and easy and cheap solution to this issue with minimal config required.

You'll need a Mikrotik router, these range in prices based on your needs, but a HAP AC2 is great if you need WiFi.
Set your ADSL router to bridge mode, disable WiFi, DHCP etc.

Update the Mikrotik. Remove Ether 2 from the Default LAN bridge. Delete the DHCP client on ether 1.

Connect Ether 1 to the Fibre CPE, and Ether 2 to a LAN port on your old ADSL router. Create a PPPOE connection with the settings your Fibre ISP gave you on Ether 1 - (Default settings include LAN NATing, Default Route, Default Distance=1, Use DNS). Create a second PPPOE connection on Ether 2 using your ADSL credentials, the only thing you need to change here is the Distance, set this to 10.

Now your router will be able to provide a default connection out of both links, favouring fibre, and when it's down switching to ADSL seamlessly. When the fibre comes back up, the shorter route will be favoured again.

Shout if you need a hand.