Newbie: Help Needed with BT Business Broadband Fibre connection to OPNsense:

[revlmh]

Hi all. I am certainly a newbie to networking but not a novice regarding software and PC-building. I wanted to build a home router using an older pc (i7-4790), 8 cores, so older but has plenty of capability. I am using the on-board motherboard and a separate Realtec card - no problems with setup etc. I have exhausted the BT-related walkthroughs (not just BT) on YouTube. I am confident that the router is set up right - I can get to the GUI from the LAN port and go through the wizard. The WAN looks to be configured correctly (I used autodetection). Here is a summary. I would welcome any help...It could be something simple.

BT fibre lead (that would go into the business router now goes into a modem), and the WAN lead goes from the (Draytek) modem to the WAN port on the router (old PC)..I am aware that this could be a newbie simple problem I have missed

... No Internet Connection: Despite the PC recognizing the Ethernet link as “Network - no internet" rather than 'Network unidentified; there’s errr...no internet access.

BT Support: BT suggested that the generic username (originally given when I first subscribed, and used for years) might be for testing purposes. They provided a new username, but the issue persists. BT were pretty unhelpful apart from this but an engineer back in the UK suggested using a Draytek modem.
Router Mode: The BT usernames and passwords work when the modem is in router mode, whether using a Draytek or TP-Link router. (The Draytek comes set in bridge mode but it can act as a modem-router).
Settings PPPOE, MTU 1492. MSS 1452, VLAN tag attached to WAN port of 101.

Troubleshooting Steps Taken:
Switched out ethernet cables - cable came with modem.
Attempted generic usernames and passwords (thanks Sheridan Computers YouTube) for BT business hub, and BT homehub - no success.
DNS Settings: Configured DNS servers manually.
Gateway Configuration: Verified WAN gateway setup - gateway is up.
NAT Configuration: Ensured NAT is enabled - Automatic outbound
Diagnostics: Used OPNsense diagnostic - Ping to 8.8.8.8 does not return.
Firewall Rules: Checked firewall rules to allow traffic from LAN to WAN.

Despite these steps, I still can’t get the internet connection to work. Any advice or suggestions would be greatly appreciated! Wondering if this could be hardware - but wary of spending any more money.

[bartjsmit]

First off - this is not fibre, no matter what BT sales and marketing tries to tell you. It sounds more like FTTC or VDSL and the Draytek is an excellent first step  Would this be a 130 by any chance?

The Realtek is a niggle but if OPNsense sees the Ethernet interface you should be fine. Your basics look to be in good shape.

Your first point of call is the PPP log:
Interfaces: Point-to-Point: Log File

It's not a given that you will have PPPoE. There is DHCP in VDSL as well (*cough* Sky *cough*). Play around with option 61 for a laugh.

Bart...

[revlmh]

Thanks Bart... much appreciated. Good to know my basic setup is okay. I tried to play around with other options - no luck. Yes, it is VDSL - and it is a Draytek 160 router. I called up the PPP log and got nothing. I have tried to play around with option 61 - i.e., going to DHCP - but I am pretty clueless here. I have a table of values from BT - Broadband IP address, Default Gateway, and Primary and Secondary DNS for the old router, but I do not quite know what I am doing with these! I am at Network for Idiots chapter one but am picking things up pretty quickly I think. Could you be a bit more specific

One thing - I ditched the idea of managing the PPPoE through the Draytek, just for a test, fixed the cable to the old router (a cheap TP-Link that has been really faithful), checked the connection to a laptop - no problem - internet over ethernet fine. However, when I take the same cable and plug it as the WAN into the new-built router, I get nothing - when I work through the wizard again. I think I should be getting double NAT.

I am wondering if this points to a hardware issue - although the WAN is coming through to a motherboard ethernet port...I have tried switching to no avail.

[bartjsmit]

Are you sure the Draytek is in modem mode? Boot your laptop off a live Ubuntu USB drive and see what appears on the ethernet port. You can make a PPP connection from the GUI: https://www.linuxbabe.com/ubuntu/create-pppoe-connection-ubuntu-16-04

You may get away with double NAT but you must tell OPNsense that your WAN has an RFC1918 IP:
Interfaces:WAN:Block private IP

[revlmh]

Thanks. Installed Ubuntu dual boot anyway - ran network manager by command line. Worked through the options. Modem not recognized - apologies did not screen grab but it would not progress. No option to put in a username and password - which is does when it detects even a wireless connection.

Checked Draytek - it is in bridge mode....

mmmm...

[bartjsmit]

Yikes! Factory reset of the modem is the next step, I guess. Did you tag your laptop ethernet with VLAN 101? I think the theory is that you access the Draytek web GUI on the base interface and do your WAN traffic over VLAN 101.

I remember a BT specific firmware for the 130 and a whole bunch of options that took a bit of googling. Obvious ones were PPPoE rather than PPPoA. Most will not apply in bridge mode.

Keep a keen eye on the lights - ACT blinking for activity and DSL steady on for a link are what you want to see.

[revlmh]

ok - we are there. I am not quite sure what solved it in the end - but for newbies like myself:
1. I purchased a double ethernet adaptor rather than a single one - intel based. Dual-Port PCIe Gigabit Network Card PCI Express Gigabit Ethernet Adapter with Intel 82576/82575 Ports PCI Express NIC Support PXE for Windows/Windows Server/Linux/FreeBSD/DOS With Low Profile. Brand: ULANSEN
2. I reinstalled Opnsense - what was interesting was that on the live-USB, it only recognized the two ports on this card, and assigned the interfaces naturally.
3. On the first install I went for double-nat, just to see if I could get a WAN IP address, and I could, but for some reason the LAN was set to 192.168.1.100
4. I worked through reassigning the LAN to 10.10.x.x. and then was able to access the router through this. I found https://www.youtube.com/watch?v=CocyuQ-AyOY Zenamor helpful.
5. I then moved across to the Draytek router in bridge mode, and logged into the GUI - which needed a change in the adaptor settings because the IP is as standard 192.168.2.1 - I note that my instructions had 192.168.1.1 Odd for such a great company, by reputation, My model is the Vigor 167 https://www.draytek.com/assets/online_manuals/pdf/DrayTek_UG_Vigor167_V1.2.pdf#:~:text=Vigor%20167%2035b%20Modem%20User%E2%80%99s%20Guide%20Version:%201.2%20Firmware. You also need to set up a static IP address which must be in the same subnet as the router - ie right click on the ethernet properties, go down to IPv4, set the PC address (top line) to 192.168.2.any-number 2-255, and then put the default gateway as 192.167.2.1 - the subnet mask sets itself if you click on any box. Then go back into your browser and you can access the router.
6. Once attached to the Draytek in bridge mode, Opnsense connected easily with my user and password - and did not need VLAN initially.
7. I noted that the speeds were slow from the internet - and looked up how to add the VLAN tag 101 - first setting up the tag, and then applying it to the WAN port. You can find help with that but I found that ChatGPT was a help because there is so much information out there.

Now to learn about networking and the options of opnsense!

We are up and running. Just hope this helps someone else. It would be interesting if anyone else can see what has been going on. The resetting of the LAN IP address to something completely different - together with the range of possible IP addresses to be assigned was a major change but I wonder if the new card was a factor as well.

Thanks bartjsmit - just hearing that I was on the right lines kept me plugging away.

[bartjsmit]

Good one Not sure you needed steps 3,4,5 since the blinkenlights on the Draytek are usually good enough.