Problem connecting to ISP (Plusnet) with Openwrt 21.02.2 on ADSL connection

Installing and Using OpenWrt
#1

ISP is PlusNet (UK ISP)
OpenWRT 21.02.2
ADSL connection

/etc/config/network file is here https://pastebin.com/4TiTFe8E

The only thing that I did that is outside of the default OpenWRT setup would be to install the pppoa package manually (I uploaded each of these to the router through Luci):

kmod-atm_5.4.179-1_mips_mips32 
linux-atm_2.5.2-7_mips_mips32 
kmod-pppoa_5.4.179-1_mips_mips32 
ppp-mod-pppoa_2.4.8.git-2020-10-03-3_mips_mips32

In Luci, the network interface that I set up to connect to the ISP just says "Unknown error FATAL_ERROR"

I tried matching the instructions from the wiki for a generic UK ISP as closely as possible but it still won't work.
Anyone have any ideas on what could be wrong?

#2

What is the openwrt device?

#3

Plusnet Sagemcom 2704N v1 (aka Plusnet Hub Zero)

#4

There is no DSL support in OpenWrt for Broadcom based routers such as 2704N

https://openwrt.org/toh/plusnet/fast2704nv1

#5

Does that mean I just can't use it as an ISP router?

I guess it's a no-go for this router. Thanks for replying.

Just a quick follow-up while I have your attention, would a TP-Link AC1750 https://openwrt.org/toh/tp-link/archer_c7 work as a main ISP router on an ADSL connection? Or is it limited to DSL only?

#6

Correct.

Only devices using Lantiq based chipset have DSL support such as modified Home Hub 5A/Plusnet Hub One available in the UK.

The C7 does not have a DSL port, so a C7 or any other router (inc. 2704n?) running OpenWrt would have to use a separate DSL bridge modem (eg. TPlink TD-W9970 in 'bridge' mode).
https://www.tp-link.com/uk/support/faq/1332/

When using a separate bridge modem on Plusnet (or BT), the external router (eg. C7) will use PPPoE protocol.

If the DSL router does not offer 'bridge' mode, then another option is to use DMZ. It is not ideal but often works well.
https://openwrt.org/docs/guide-user/network/wan/dmz-based-bridge-mode
I think Plusnet firmware on 2704n does offer DMZ.

#7

That's awesome, thanks for the explanation.

#8

The https://openwrt.org/toh/bt/homehub_v5a is still available (the initial flashing is not trivial, you might want to prefer pre-flashed devices) for rather little money in the UK, which would be the best option with an included xDSL modem (yes, it's not exactly the fastest device/ SOC, but plenty for an ADSL connection).

1 Like
#9

I have a pair of those bt hub5s spare that i've yet to throw on ebay. they just need a current flash of latest openwrt (i think they both have RC versions atm on). (i also have the original NAND dumps for both incase u wanted to return them back to BT software)