Setting up alternative router on Vodafone Fibre

Hi,

I have a Fibre connection with Vodafone, with a Static IP.

I have the Fibre modem box, which then over ethernet connects to the standard VF router (Huawei Home Gateway HG659).

Everything works fine; expect for the fact this router/home gateway does not support LAN Loopback, which causes problems for my internet network

For background and "Why?" -- I am running a server on a publicly accessible IP, but without LAN Loopback funtionality, when within the LAN you cannot access the server - common problem and LAN Loopback feature resolves this... but this doesn't support LAN Loopback)

So I am trying to configure another router instead and have having trouble.

Using the TP-Link TD-W8980; this is a modem router ("N600 Wireless Dual Band Gigabit ADSL2+ Modem Router") but also has "Wireless Router Mode", i.e. turning off ADSL as just acting as my router.

Wireless Router Mode: https://goo.gl/gCUN9y

Once in this mode, within WAN settings I have entered my static IP, primary and secondary DNS servers and the default gateway; all of which were taken from the Ethernet Settings displayed on the standard Vodafone HG659:

IPv4 address: 203.xxx.xxx.51Subnet Mask: 255.255.255.0 (this isn't shown on the HG659 but was confirmed with a phone call to VF IT)IPv4 primary DNS server: 203.109.191.1IPv4 secondary DNS server: 203.118.191.1IPv4 default gateway: 203.118.129.254

Screenshot: https://goo.gl/QKr9EN

The Status screen then looks ok: https://goo.gl/IyWZP9 -- reports connected.

But, nope, it doesn't work; there is no internet connection available on the LAN.

The logs also report a few notices: https://goo.gl/7BMXkl

And the Diagnostic Tool cannot ping the default gateway (testing WAN): https://goo.gl/jyNaLY

I also tried the same as above, but left the optional settings (gateway and dns) blank: https://goo.gl/ZVW9NJ

Same issue though, no internet connection on the LAN - PCs on the LAN cannot ping the gateway, google etc.

I have tried the same on another router (Netgear WNR2000) again with no luck.

I rang VF technical support and they could offer no help at all; just told me all the settings I need are shown in the Internet_Ethernet screen of the HG659 (i.e. IP, gateway, DNS).

So any advice would be most appreciated, whether these routers would never support this set up for whatever reason (is the VF fibre modem > WAN different from "usual ASDL modem?" or do I have a setting wrong somewhere? Part of me thinks the gateway on the router should be a local IP address of the fibre modem but not sure what this is (it's obviously not on the LAN created by the router 192.168.1.x).

At the same time as I have the TP Link router (WAN port (LAN4/WAN)) connected to the Fibre Modem (LAN port 1), I have the HG659 connected (WAN port) as well using LAN 4 port of the Fibre modem, and it works fine.

Or, if no idea why it's not working, can anyone recommend a Fibre Router which definitely works with VF Fibre and supports LAN loopback?

Many thanks in advance

Rob