FTTP Connection drops every minute or so Fritz!box 7590 3490

Hello
New on here with very limited IT knowledge but I�m hoping some kind soul with expert knowledge may be able to point me in the right direction to address my problem.
Have an FTTP package from Zen which worked flawlessly until Saturday evening Jan 18 when the internet became unusable. Spent most of Sunday talking to Zen support who took me through several tests. The identified problem is that my router FB7590 was dropping the connection every minute or so. Replaced cables between ONT and Router and PC. Rebooted ONT, Router, PC. Reset 7590 to factory settings � couldn�t then get it going (which is not surprising as I couldn�t get it going when I first put it inline � eventually I imported the settings from a previous FB3490 and it then worked). Next I took the 7590 out and replaced with the old 3490. Same story on the line disconnections. Finally I connected the PC directly to the ONT and everything worked again. This is as far as Zen could take me being that the problem appears to be clearly my side of the ONT with either the router or with kit attached to it. Speculation from Zen is that it may be a faulty piece of kit connected to the router that is introducing voltage where voltage is not supposed to be and consequently causing problems with the router. I�m tearing my hair out and at a complete loss about where to go next.
Any ideas would be most welcome.
Thank you.

It's a process of elimination which looks like it needs to concentrate on the links through the router. As a first step, did you just swap routers over or did you change the PSU as well? If you just swapped routers, do you have another PSU you can use as a test?

Thought would be to check the clock is set right, am wondering if an incorrect clock is causing the PPPoE session to expire and be reacquired

Many thanks GP and yes I used different PSU's on each router.

Could it be that the FritzBox is configured to monitor some remote IP address to test the link is up, and if it fails to respond within a certain time, it resets the connection?

That would be a dubious thing to do, but I have seen worse.

(If you have a switch with port mirroring, you could put it between the FritzBox and the ONT and monitor the mirror port with tcpdump or wireshark to see what's going on)

Thanks, I cant see where it actually shows the time in the router settings, however in the Region and Language Time Zone section it is set to automatcally set the time as soon as a connection is established.PC time is also set from the internet.

One interesting point that may or may not be relevant is that I notice in the Overview section - Interfaces, it shows DSL as disabled, yet the LED for DSL on the box itself is lit.

Thanks. Unfortunately I have a simple Netgear Switch GS116E which, as far as I can determine, doesn't come with port mirroring.

In reply to a post by rogeroakley:

>however in the Region and Language Time Zone section it is set to automatcally set the time as soon as a connection is established

I have seen some ISPs block NTP for client connections (as "protection" against some forms of DoS amplification). It might be worth setting the router to local time only just to rule this out.

Re the Netgear: the "Smart Managed Pro" devices (e.g. GS108Tv2, GS110TP, GS724Tv4) have a full managed feature set including SNMP, telnet CLI and port mirroring. But I think yours is "Smart Managed Plus" which is very basic by comparison.

Thanks. I will set the time manually.

Fine on the switches. I have a GS308T arriving this afternoon, then it will be a case of me doing homework to figure out how to do what you're suggesting.

Just struck me that it is all rather pointless to try and troubleshoot this if both routers are in fact fried so I'll take one over to my neighbour and hook it up to his connection (also FTTP with same ISP) and see what happens. That would at least confirm the status of the router.

You can�t set the time manually on the FB, it has a default time server entry in network settings which can be changed. If you only have the FB connected to the ONT on the FB LAN1 port, other FB ports disconnected, can you connect via WiFi ok, does the FB still reset?

In reply to a post by steve25:

You can�t set the time manually on the FB, it has a default time server entry in network settings which can be changed. If you only have the FB connected to the ONT on the FB LAN1 port, other FB ports disconnected, can you connect via WiFi ok, does the FB still reset?

Thanks. Whilst I was swapping routers back and forth with Zen support, they asked me to reset one. I put the 7590 back inline, did the reset and it wouldnt then go online. The reason, as I found out yesterday was that I had plugged the ONT into LAN1 which whilst correct for the 3490, is not for the 7590. When I plugged into the WAN port it then worked, so I'm back on that now. Same problems persist. Earlier this morning I unplugged everything from the router so running on wifi only and the line disconnects persist.I have noticed, however that there is now a longer up time between disconnects. Typically 4 to 25 mins. Yesterday and previous to then, the disconnects were every minute or so.

Additionally in the night, I see that it connected at 01:02 and didnt drop until 03:25 and the reason for this drop was "Clearing connection briefly to prevent the internet service provider from disconnecting you in the immediate fiuture" Never seen that one before. The connection reset 1 second later and it continued connected until 08:16. Coincidentally, this is exactly the time I unplgged the everything from the router except the ONT.

Beginning to think I might have to look in the yellow pages for a specialist in this area to have a look for me.

In reply to a post by candlerb:

Re the Netgear: the "Smart Managed Pro" devices (e.g. GS108Tv2, GS110TP, GS724Tv4) have a full managed feature set including SNMP, telnet CLI and port mirroring. But I think yours is "Smart Managed Plus" which is very basic by comparison.

The GS116Ev2 is Smart Managed Plus (and does port mirroring - I have one and do use the feature from time to time). The GS116 (not been made in quite a while now) and GS116v2 are unmanaged, and the GS116LP and GS116PP are also unmanaged but have PoE.

The easiest way to differentiate them is the GS116 and GS116v2 are in "Netgear purple" where as the the GS116Ev2 is in a silvery grey. The PoE ones have yellow around the switch ports to indicate they are PoE capable.

Post deleted by steve25

Edited by steve25 (Wed 22-Jan-20 10:46:56)

In reply to a post by rogeroakley:

In reply to a post by steve25:

You can�t set the time manually on the FB, it has a default time server entry in network settings which can be changed. If you only have the FB connected to the ONT on the FB LAN1 port, other FB ports disconnected, can you connect via WiFi ok, does the FB still reset?

Thanks. Whilst I was swapping routers back and forth with Zen support, they asked me to reset one. I put the 7590 back inline, did the reset and it wouldnt then go online. The reason, as I found out yesterday was that I had plugged the ONT into LAN1 which whilst correct for the 3490, is not for the 7590. When I plugged into the WAN port it then worked, so I'm back on that now. Same problems persist. Earlier this morning I unplugged everything from the router so running on wifi only and the line disconnects persist.I have noticed, however that there is now a longer up time between disconnects. Typically 4 to 25 mins. Yesterday and previous to then, the disconnects were every minute or so.

Additionally in the night, I see that it connected at 01:02 and didnt drop until 03:25 and the reason for this drop was "Clearing connection briefly to prevent the internet service provider from disconnecting you in the immediate fiuture" Never seen that one before. The connection reset 1 second later and it continued connected until 08:16. Coincidentally, this is exactly the time I unplgged the everything from the router except the ONT.

Beginning to think I might have to look in the yellow pages for a specialist in this area to have a look for me.

�Clearing connection briefly� is a feature that can be turned off, in Internet, account settings - screenshot below. Untick �delay disconnection� . Still doesn�t explain your main problem, I suggest taking either of your routers to the neighbours you mentioned and if one of them works ok there then going back to Zen.

Screenshot

Edited by steve25 (Wed 22-Jan-20 11:00:52)

UPDATE:
Thanks to all who contributed. I finally got to the bottom of what was dropping my connection. An IP camera connected via WiFi. Unbelievable! It appears the camera was uploading huge amounts of data causing the line to drop continuously. In the 10 days or so I was having problems I uploaded over 250GB of data, whereas in a full month I would normally upload around 10-12GB. What is worrying is just what data was being uploaded.

In any event, removing the IP camera solved the problem immediately. Both routers are fine and not damaged and my connection is now stable.

If the camera was streaming video to the cloud somewhere then 250GB over 10 days isn't that much. It is only around 290Kbps - to put it in context an HD video stream would run at somewhere around 3000 - 5000Kbps. Even if it was only fairly regularly uploading images it would be pretty easy to consume that amount of data in 10 days.

Likelihood is your camera uploads images or video to the cloud (or perhaps you had the password set to the default and one of the many websites out there found your IP and were displaying the images from your camera to anyone that wanted to watch).

Not saying this was the case, but ...
A while back there was a huge number of IP cameras being involved with botnets.