Lede device as VDSL Modem only

Hello all,
I need to turn a router with a built in VDSL2 modem into a modem only so that all traffic and all other routing, firewall, dhcp etc will be carried out by another device connected to one of its LAN ports.

What are the steps to achieve this and to forward all traffic to the other actual router?

The router I would like to use as modem only is a BT HomeHub with a built-in VDSL2 modem and Lede/OpenWrt installed.

Thanks in advance

Set Your WAN Interface Protocol to UnManaged
Disable DHCP on your LAN Interface
Bridge Your LAN interface to Your WAN

If you wish to configure the HH5a (LEDE) to 'bridge modem mode' to attach to an external router, refer to section 9.8 of the install guide for HH5a:

fwiw, only the BT Business Hub 5 with stock BT firmware has optional 'bridge mode' option. (Not available in Home Hub 5)

Thanks all

I have to use Lede because it's what I have now on my HH5a.

Wouldn't setting the WAN Interface Protocol to Unmanaged prevent the modem from authenticating or are you saying that his would then be done by the actual router but merely using the physical modem on the HH5a?

In terms of disabling other functionalities, do I just stop the services such as dnsmasq and firewall from starting up? I need it to work as a dumb modem. I would normally use the Openreach modem but that's lost somewhere and may have been thrown away by the other half

Thanks but I already have LEDE on my HH5. I no longer have the original BT firmware which wouldn't have allowed me to bridge anyway.

Just follow the instructions in section 9.8 for setting up bridge modem mode. You will end up with a HH5a that is a direct substitute for the Openreach VDSL2 bridge modem, with the bonus of being able to manage the modem via LAN2 port.

yes, you would indeed have to configure your external router (wired to the bridge modem) to connect to your ISP. eg. use PPPoE prototcol for BT/Plusnet/EE and most other ISPs. Use 'dhcp' for TalkTalk.

Great advice. Thank you all very much indeed.