CHAP authentication error

At 23:00 last night, our connection dropped and the router logs indicated there was a CHAP authentication error right the way through to just after 6AM this morning. But then at 09:30 the connection dropped again and now won’t reconnect due to the same CHAP authentication error.

If I use my laptop to connect directly to the ONT and attempt to establish a PPPoE connection (which I’ve setup previously and had working), it fails to connect and I get a mixture of RAS error codes for each connection attempt. They are 629, 691 and 829.

There is no red LOS on the ONT.

Zen’s status page doesn’t indicate any overnight maintenance affected our circuit or exchange, so I’m guessing an upstream exchange was affected, although Zen told me our circuit goes to the Ellesmere Port exchange and then via the CableLink directly to London.

I’ve been trying to get through to technical support on the phone for 20 minutes but so far nothing.

Zen has just posted an outage that explains things:

https://servicealerts.zen.co.uk/active/5/8218

The annoying thing is, they moved our circuit off their equipment in the exchange a few months ago, which they suggested doing, to rule out our packet loss issue being down to them. As it turned out, the change made no difference, proving Openreach to be at fault for the packet loss, but when I asked Zen to move us back to their equipment, they didn’t. Had they moved us back, it wouldn’t be down today.

My thought process there was when fault finding, you make a change, test it, and if it hasn’t solved the issue then undo the change and move on to the next thing to change.

I would still double check with Zen that the BTW backhaul issue is connected to your current issue, the last thing you want is that being fixed and you still have no service.

I have done, they confirmed it’s related, and they can see my request to migrate back to Zen equipment in May that was never actioned for some reason. I can’t work from home today because of their failure. Not what I expect from Zen, especially as I’ve always known them to be really professional and provide a top quality service.

Yes I agree - when trying unrelated fixes in sequence, test one at a time and reverse if it doesn't solve the issue, otherwise you don't know if you are compounding the problem.

The exception is if the original setting was actually wrong anyway even if it wasn't the cause of the current problem, but you make a separate note of why that needed changing.