Hi, I have came across an issue that I'm having a really hard time solving. My setup is a Thinkcentre E73 with two intel PCIe NICs, OPNsense 26.7.2_2. ISP is BT with FTTP and PPPoE logon to the ONT. If you need any more information I am happy to provide but I think that's all that's relevant
Two days ago my area had two back-to-back powercuts and the router did not recover. We have had power cuts before and usually it autoboots (UEFI setting) and gets connection once the power is back. This time it did not autoboot, and after manually starting it there was no connection to the internet. The router did get assigned a WAN IP, the ONT has power, PON, and LAN lights green. Everything seems as if nothing is wrong but it is impossible to ping the WAN IP from another network, and it is impossible to ping out of either the router itself or any device inside the network.
Things I have tried:
- Revert to a snapshot (based on 26.1 so admittedly a little old, perhaps restoring my config from the current version makes sense?), my reasoning was that if a powercut caused some sort of corruption etc this would rule it out
- Resetting the ONT
- Testing connection from within OPNsense to rule out issues between devices and the router
Notes:
- The router not automatically booting is concerning because AFAIK it was working fine before this event, potentially means a hardware issue?
- I have a dynamic IP and the WAN IP given to the router after the power cut is different to what it had before, which makes me think it really did talk to BT and get assigned something, meaning its likely not a loose cable or failure of the ONT or BT.
- I know the OPNsense version is a little out of date but updating is currently out of the question for obvious reasons
Usually I have no problem troubleshooting stuff but this has left me completely stumped and I need some outside perspectives.
UPDATE:
I have switched back to fully stock ISP hardware and it is suffering the exact same problem making me think the issue is more likely with the ONT or ISP. So I will contact them and provide an update after they have been
UPDATE 2:
BT said their hub (WAP/router/switch) was dead and replaced it. Their new hub (just stock ISP hardware no OPNsense etc involved, but with all my usual ethernet devices plugged back into it) was still misbehaving, some devices could access the internet some couldn't. The BT engineer tried unplugging all other ethernet devices from the switch in the BT hub and this fixed it... Currently just on stock ISP hardware, I still don't have physical access so I am quite limited but I will ask someone to plug devices (nas, PC, OPNsense router etc) back into the switch one-by-one and see which one is the cause. Possibly a surge damaged a device in such a way that its causing others to misbehave? The old BT hub was dead so if it killed one its not unlikely something else got damaged.
Before trying anything else, you would have to solve that boot issue.
Did you install on ZFS, because UFS can get corrupted on power outages? That is the reason why ZFS is recommended (https://docs.opnsense.org/manual/install.html). That may already be the explanation and the remedy is clear.
Yes my install is on ZFS, I can't currently check the boot issue due to not having physical access. I usually configure everything over wireguard but everything I have mentioned since the connection issue has been done on a video call with people who do have physical access, they're not the most technical and plugging a mouse and keyboard in etc to check the bios is out of scope. It is ridiculous I know but my options are limited at the moment. I do have the ISP router ready to go as a backup if this can't be fixed remotely
Quote from: recess7139 on September 13, 2026, 07:32:18 AMRevert to a snapshot (based on 26.1 so admittedly a little old, perhaps restoring my config from the current version makes sense?), my reasoning was that if a powercut caused some sort of corruption etc this would rule it out.
That does not solve any issues with the storage and/or filesystem : Only a reinstall does and don't forget the smartctl -a /dev/<whatever> output too! ;)
With ZFS you could try a scrub first ofcourse...
QuoteThe router not automatically booting is concerning because AFAIK it was working fine before this event, potentially means a hardware issue?
That's a BIOS/UEFI setting so double check that first...
QuoteI have a dynamic IP and the WAN IP given to the router after the power cut is different to what it had before, which makes me think it really did talk to BT and get assigned something, meaning its likely not a loose cable or failure of the ONT or BT.
You could double check if it's a CG-NAT IP Address or not : https://en.wikipedia.org/wiki/Carrier-grade_NAT#Shared_address_space
QuoteUPDATE:
I have switched back to fully stock ISP hardware and it is suffering the exact same problem making me think the issue is more likely with the ONT or ISP.
So I will contact them and provide an update after they have been
Good luck! :)
Quote from: meyergru on September 13, 2026, 09:00:47 AMDid you install on ZFS, because UFS can get corrupted on power outages?
IMHO a lot of that can be avoided with a decent SSD that has
FULL Power Loss Protection done by onboard capacitors, but they cost a pretty penny these days even if you can find the right brand and model :'(