Intermittent loss of connectivity despite replacing everything

[#1]

Greetings everyone,

I'm hoping that someone can help with a really strange intermittent outage which is ongoing. For the past week my full fibre network has been almost unusable for streaming, general browsing etc (web pages don't load, or hang when downloading images) and I frequently lose connectivity. Speed tests generally don't work and when they do, I get a strong download speed close to the max but no upload at all. I run a firewalla firewall which reports Plusnet disconnects and loss of WAN connectivity about every 2 minutes.

From 22 Dec, my Fing network monitor had also started reporting daily outages between 1 - 10 minutes. These continued until the end of the month when I installed a new wifi mesh node and rebooted the system which also restored max download and upload speed test performance (I don't have Fing daily test data yet for Jan). Then last Wednesday, I started losing connectivity all the time. 

I checked all the connections, changed cables, rebooted my router and wifi mesh - no change - then took out my firewalla (used as a router) and ran my Deco as router and the issue persisted. I got a Plusnet router sent and it persisted, even with no other network equipment connected and tested using a laptop cabled into the back of the router. Plusnet have run checks their end, a Plusnet engineer visited and confirmed the issue (the hub shows connectivity is fine, but web pages etc don't load. I've had an Openreach engineer on site all day and he replaced the ONT and external cabling, connected the cable to different blocks on the telegraph pole, replaced the cable from the telegraph pole to my house, checked the fibre to the exchange and set up a circuit to a different part of the exchange, but despite all that, the issue is persisting!

Openreach are going to do some more checks on their network, but there may be something about the Plusnet network which is causing the issue (although the team I previously spoke to (3 people on different occasions) about the fault said the readings were fine).

If anyone knows what could be the issue, or can look into this from the Plusnet network side, that would be appreciated!

Many thanks

Tom 

[#2 · Accepted solution]

Update: The Openreach engineer came back this morning and did some more checks, enabling them to rule out a fault on the Openreach network. He then spent a long time on the phone to Plusnet running through everything which he'd done. Luckily he persisted and wouldn't close the ticket, or let Plusnet close it. After doing a factory reset of the router, he mentioned my static IP address which Plusnet couldn't see on their system. I added this through the online portal on 1 July after upgrading to full fibre and it had been running OK up to now.

Plusnet looked into it further and identified that this mismatch was causing the problem. Removing the static IP stopped the connection from dropping and restored the service! I can't see the £5 charge on my bill at the time, so something must have gone wrong with it at the time, although I'm not sure why it suddenly caused the issue. 

Massive kudos to the Openreach engineer who wouldn't stop until he helped to resolve it. 

[#3]

Removing the static IP stopped the connection from dropping and restored the service! I can't see the £5 charge on my bill at the time, so something must have gone wrong with it at the time, although I'm not sure why it suddenly caused the issue. 

Strange why it should suddenly cause a problem ?. Problems will occur if two connections are assigned the same static IP. I've only ever heard of this happening where a Plusnet router has been passed on to another user. The router is attached to the original account, so when it connects after a factory reset, it will automatically configure with the original account and thus you have two connections on the same account. If that account happens to have a static IP, then both connections will be assigned it and you have major problems. Where the account is using dynamic IP, there is no problem as each connection (even on the same account) will be assigned a different IP.