Internet connection keeps dropping every 30 minutes

[redorbluepill]

Hi Virgin Media Community,

I experience a very weird problem with my connection. It keeps on dropping out every 30 minutes, exactly on the dot. Which most of the time causes me to loose the virtual desktop for work.

I have a long journey of root cause analysis behind me and finally decided to do a longer term speedtest with speedtest-cli and auto-speedtest, running every 5 minutes on my Raspberry Pi (static IP address) connected via network cable to the Virgin Media router. This resulted in the following 

Strangly enough, for every full hour and half hour, my connection drops. I did run it every minute the day before and it confirmed it's excactly at these times.
Please note that the additional drop at shortly after 9am is the result of rebooting the VM router. However, the connection still dropped out at 9.30am, 10am, and 10.30am.

I confirmed this assessment with another of my Debian machines at home. It also looses the connection.
To further exclude any dodgy ethernet cables, I also connected another MacOS machine via WiFi to the VM router and ran the speedtest. Same result: drop outs every half hour. I have to admit though that this will need to contact the DHCP and DNS server connected via ethernet cable (and ethernet switch in-between) to the VM router.

I just have no idea what could cause this. I reckon I need a Virgin Media engineer to re-test the connection?

My set up:
I have a Virgin Media router, which functions as Wifi-Hotspot and router. Combined with a Raspberry Pi, which runs PiHole with DHCP server and unbound DNS service. Most of my machine are connected via ethernet cable, but some machines connect via WiFi.

What I have tried so far:
- Double checked my connection with ping 8.8.8.8 to ensure there is a problem with the connection and not the DNS
- Checked my cron jobs on my Raspberry Pi to make sure there are no big services running every 30 minutes. That doesn't seem to be the case
- Restarted my Raspberry Pi
- Checked my DHCP settings and the leases to my machines and the leases are for a week.
- Restarted the VM router and moved the power supply to a seperate power point (no other devices on this power point)
- I have a BQM from Thikbroadband running: Broadband Quality Monitor from Thinkbroadband 
- And now I do have a speedtest running every 5 minutes on my Raspberry Pi and my seperate Debian machine.

What I haven't done yet is:
- Set up my MacOS device with a static IP address and 8.8.8.8 as DNS server and perform testing

Does anyone have any additional ideas?

Many thanks in advance!

[Adduxi]

That's a shocking BQM.

Firstly check with Area faults on 0800 561 0061 or if you have a VM landline 150

Also can you post the network log, power levels and Pre and PostRS errors from the Hub.  Don't use screenshots, just copy and paste the text.

[redorbluepill]

Thanks for your reply Adduxi,

my router's network log for the last few days (removed the MAC addresses):

Time Priority Description

04/11/2021 09:27:27	notice	LAN login Success;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
04/11/2021 09:16:20	critical	No Ranging Response received - T3 time-out;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
03/11/2021 19:59:30	notice	LAN login Success;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
03/11/2021 15:32:54	critical	No Ranging Response received - T3 time-out;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
03/11/2021 11:50:59	notice	DHCP Renew - lease parameters tftp file-cmreg-vmdg505-bbt057-b.cm modified;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
03/11/2021 11:50:59	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
01/11/2021 12:51:23	critical	No Ranging Response received - T3 time-out;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
30/10/2021 23:51:0	notice	DHCP Renew - lease parameters tftp file-cmreg-vmdg505-bbt057-b.cm modified;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;

And here are the power levels and Pre and PostRS errors:

Downstream bonded channels

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID

1	139000000	-0.5	38	256 qam	1
2	147000000	-0.7	38	256 qam	2
3	155000000	-0.7	40	256 qam	3
4	163000000	-0.4	40	256 qam	4
5	171000000	-0.4	40	256 qam	5
6	179000000	0	38	256 qam	6
7	187000000	0.2	38	256 qam	7
8	195000000	0.5	40	256 qam	8
9	203000000	0.7	40	256 qam	9
10	211000000	1	40	256 qam	10
11	219000000	1.2	40	256 qam	11
12	227000000	1.5	40	256 qam	12
13	235000000	1.5	40	256 qam	13
14	243000000	1.5	40	256 qam	14
15	251000000	1.5	40	256 qam	15
16	259000000	1.2	40	256 qam	16
17	267000000	1	40	256 qam	17
18	275000000	1.5	40	256 qam	18
19	283000000	1.4	40	256 qam	19
20	291000000	1.5	40	256 qam	20
21	299000000	1.7	40	256 qam	21
22	307000000	1.7	40	256 qam	22
23	315000000	2.4	40	256 qam	23
24	323000000	2.7	40	256 qam	24

Downstream bonded channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors

1	Locked	38.9	11	0
2	Locked	38.9	7	0
3	Locked	40.9	4	0
4	Locked	40.3	3	0
5	Locked	40.9	5	0
6	Locked	38.9	4	0
7	Locked	38.9	5	0
8	Locked	40.3	22	0
9	Locked	40.3	16	0
10	Locked	40.3	6	0
11	Locked	40.3	5	0
12	Locked	40.3	6	0
13	Locked	40.3	6	0
14	Locked	40.9	5	0
15	Locked	40.9	5	0
16	Locked	40.3	8	0
17	Locked	40.3	4	0
18	Locked	40.3	6	0
19	Locked	40.3	4	0
20	Locked	40.3	6	0
21	Locked	40.3	0	0
22	Locked	40.9	5	0
23	Locked	40.3	5	0
24	Locked	40.3	7	0

I think I might need to mention that the Virgin Media engineer originally (end of last year) connected us to our neighbour's connection and said that someone would do it properly in a few weeks time. Not sure that happened and if that is a potential factor?

[redorbluepill]

According to the hotline, there are no area broadband issues...

[redorbluepill]

I now also checked with a MacOS device with a static IP address and 8.8.8.8 as DNS server. Directly connected to the VM router per WiFi. Same issue persists. So I think I can exclude any internal issues with my setup.

It looks like the problem lies somewhere with Virgin Media. At least starting at the VM router and it's connection to the VM network.

[jbrennand]

Post the Upstream data as well

[redorbluepill]

Hi John,

thanks for your comment.

Here you go:

Upstream bonded channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID

1	25800000	50.3	5120	64 qam	6
2	32599996	48.3	5120	64 qam	5
3	39400000	48.3	5120	64 qam	4
4	46200043	48.3	5120	64 qam	3

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1	ATDMA	0	0	1	0
2	ATDMA	0	0	1	0
3	ATDMA	0	0	0	0
4	ATDMA	0	0	0	0

[jbrennand]

Not too bad. looks like something at the VM end - there was a similar thread recently with a similar "saw tooth" pattern (below) - not sure if a Hub4 cured it and also how relevant it is to your regular pattern (there was another thread with that a week or two ago - but I dont have it to hand)

Alls I can suggest is to disconnect everything and just have the Hub in router mode for a few hours and see if the patterns disappear or remain. If they remain you need VM to investigate. If they do go away - add your connections in one by one until they reappear and then there lays the issue.

https://community.virginmedia.com/t5/Networking-and-WiFi/Superhub-2ac-continual-reboots-in-evenings/...

[redorbluepill]

Thanks John.

Yeah, good call. Will do on the weekend. Disconnect everything and put the Hub 3 in router mode to disable WiFi. Then connect my laptop directly and see if the problem is still there.

I also called Virgin Media directly and a technician is now looking into it. So fingers crossed...

[Kath_F]

Hi redorbluepill, 

Thanks for your post and apologies to hear that you are having an issue with dropouts. 

We won't be able to fix this remotely so I would like to arrange for an engineer to come to take a look at this for you. I just need to confirm the address to ensure we are booking the visit on the correct account. 

I have sent you a private message regarding this. Just click on the little plum envelope at the top right hand side of the page to access your inbox.

Thanks,