Random Port 1 Drops using Hub 4 in modem mode

[liquidkool]

Hi All,

I have been having an issue over the last couple of months where all of a sudden I was getting random drops to my internet connection throughout the day and evening. Unrelated to contention as the times would be even into the late evening / early mornings.

My setup I use the Hub 4 in Modem mode and have a Linksys WRT3200ACM with OpenWrt running on it. I have set up monitoring on the router. I have gone so far as to change the cable between the router and the hub, change the firmware of the router (Upgraded and downgraded), even change the router with another and still have the same issue. Virgin sent over an engineer and they replaced the Hub. The rest of the day the Hub was fine, then it looks like it must have got an update early one morning and reboot (As I could see this on the monitoring on the Router), and since then this issue has come back. Not as frequent, but from experience before, after rebooting the Hub it would work for about a week, but slowly the drops would become more frequent.

The monitoring I have in place is running pings to cloudflare DNS, Google DNS and the BBC website, and all drop out at the time this occurs. Also the logs on the router are showing that the link starts flapping at that time. It shows that the link to the hub drops and comes back numerous times over about a 30 seconds, though can last for about 2 minutes.

One time I saw this occur I was on the interface section of the OpenWRT gui and noticed that the IP address on the WAN port for the router changed from the usual Internet IP address to 192.168.100.1. This was for about a second or two and then flipped back to Internet IP address you would expect.

When the engineer came out, he did mention he had spoken to some customers he had been to that they had something like this, but could not confirm fully if this was the exact same issue, but sound close enough.

Is there some software/firmware update has been released to these hubs that potentially makes Modem Mode a little unstable? If there are any Virgin Media Technical people reading this I would happy to chat to them to if they would like to get more details on this.

Has anyone else had this type of behaviour over the last couple of months ?

Sorry for the long post.

[jbrennand]

Just keep pressing the submit button and it should go.

If not - split the data into 2+ posts and send them.

[liquidkool]

3.0 Downstream channels

Channel	Frequency (Hz)	Power (dBmV)	SNR (dB)	Modulation	Channel ID
1	138750000	2.8	40.4	QAM256	1
2	146750000	2.6	40.9	QAM256	2
3	154750000	2.3	40.4	QAM256	3
4	162750000	2.7	40.4	QAM256	4
5	170750000	2.7	40.4	QAM256	5
6	178750000	2.4	40.4	QAM256	6
7	186750000	2.3	40.4	QAM256	7
8	194750000	2.5	40.4	QAM256	8
9	202750000	2.9	40.4	QAM256	9
10	210750000	3.1	40.4	QAM256	10
11	218750000	2.7	40.4	QAM256	11
12	226750000	2.5	40.9	QAM256	12
13	234750000	2.3	40.4	QAM256	13
14	242750000	2.2	40.4	QAM256	14
15	250750000	2	40.4	QAM256	15
16	258750000	1.9	40.9	QAM256	16
17	266750000	2	40.4	QAM256	17
18	274750000	2.5	40.4	QAM256	18
19	282750000	1.8	40.9	QAM256	19
20	290750000	1.3	40.4	QAM256	20
21	298750000	1.3	40.4	QAM256	21
22	306750000	1.7	40.9	QAM256	22
23	314750000	1.7	40.4	QAM256	23
24	322750000	0.8	40.4	QAM256	24
25	330750000	0.6	40.4	QAM256	25
26	338750000	0.9	39	QAM256	26
27	346750000	0.9	39	QAM256	27
28	354750000	1	39	QAM256	28
29	362750000	1	39	QAM256	29
30	370750000	1.2	38.6	QAM256	30
31	378750000	1.1	39	QAM256	31

[liquidkool]

3.0 Downstream channels

Channel	Lock Status	RxMER (dB)	Pre RS Errors	Post RS Errors
1	Locked	40.366287	0	0
2	Locked	40.946209	0	0
3	Locked	40.366287	0	0
4	Locked	40.366287	0	0
5	Locked	40.366287	0	0
6	Locked	40.366287	0	0
7	Locked	40.366287	0	0
8	Locked	40.366287	0	0
9	Locked	40.366287	0	0
10	Locked	40.366287	0	0
11	Locked	40.366287	0	0
12	Locked	40.946209	0	0
13	Locked	40.366287	0	0
14	Locked	40.366287	0	0
15	Locked	40.366287	0	0
16	Locked	40.946209	0	0
17	Locked	40.366287	0	0
18	Locked	40.366287	0	0
19	Locked	40.946209	0	0
20	Locked	40.366287	0	0
21	Locked	40.366287	0	0
22	Locked	40.946209	0	0
23	Locked	40.366287	0	0
24	Locked	40.366287	0	0
25	Locked	40.366287	0	0
26	Locked	38.983261	0	0
27	Locked	38.983261	0	0
28	Locked	38.983261	0	0
29	Locked	38.983261	0	0
30	Locked	38.605377	0	0
31	Locked	38.983261	0	0

[liquidkool]

3.1 Downstream channels

Channel	Channel Width (MHz)	FFT Type	Number of Active Subcarriers	Modulation (Active Profile)	First Active Subcarrier (Hz)
159	94	4K	1840	QAM4096	424

3.1 Downstream channels

Channel ID	Lock Status	RxMER Data (dB)	PLC Power (dBmV)	Correcteds (Active Profile)	Uncorrectables (Active Profile)
159	Locked	42	1.7	2705512138	0

[liquidkool]

3.0 Upstream channels

Channel	Frequency (Hz)	Power (dBmV)	Symbol Rate (ksps)	Modulation	Channel ID
1	43100000	50.5	5120 KSym/sec	64QAM	2
2	23600000	48.5	5120 KSym/sec	64QAM	5
3	30100000	49	5120 KSym/sec	64QAM	4
4	36600000	49.5	5120 KSym/sec	64QAM	3
5	49600000	50.5	5120 KSym/sec	64QAM	1

3.0 Upstream channels

Channel	Channel Type	T1 Timeouts	T2 Timeouts	T3 Timeouts	T4 Timeouts
1	US_TYPE_STDMA	0	0	0	0
2	US_TYPE_STDMA	0	0	0	0
3	US_TYPE_STDMA	0	0	0	0
4	US_TYPE_STDMA	0	0	0	0
5	US_TYPE_STDMA	0	0	0	0

3.1 Upstream channels

Channel	Channel Width (MHz)	Power (dBmV)	FFT Type	Modulation
6	10.0	44.5	2K	QAM8

3.1 Upstream channels

Channel	Channel Type	Number of Active Subcarriers	First Active Subcarrier (Hz)	T3 Timeouts	T4 Timeouts
6	OFDMA	200	53.9	0	0

[liquidkool]

Also noticed on my router that the WAN interface started flapping again:

Sun Feb 12 02:18:19 2023 daemon.notice netifd: Network device 'wan' link is down
Sun Feb 12 02:18:19 2023 daemon.notice netifd: Interface 'wan' has link connectivity loss
Sun Feb 12 02:18:19 2023 kern.info kernel: [1817912.101081] mv88e6085 f1072004.mdio-mii:00 wan: Link is Down
Sun Feb 12 02:18:25 2023 daemon.notice netifd: Network device 'wan' link is up
Sun Feb 12 02:18:25 2023 daemon.notice netifd: Interface 'wan' has link connectivity
Sun Feb 12 02:18:25 2023 kern.info kernel: [1817918.793089] mv88e6085 f1072004.mdio-mii:00 wan: Link is Up - 1Gbps/Full - flow control rx/tx
Sun Feb 12 02:18:58 2023 daemon.notice netifd: Network device 'wan' link is down
Sun Feb 12 02:18:58 2023 daemon.notice netifd: Interface 'wan' has link connectivity loss
Sun Feb 12 02:18:58 2023 kern.info kernel: [1817951.824350] mv88e6085 f1072004.mdio-mii:00 wan: Link is Down
Sun Feb 12 02:19:14 2023 daemon.notice netifd: Network device 'wan' link is up
Sun Feb 12 02:19:14 2023 daemon.notice netifd: Interface 'wan' has link connectivity
Sun Feb 12 02:19:14 2023 kern.info kernel: [1817967.967482] mv88e6085 f1072004.mdio-mii:00 wan: Link is Up - 1Gbps/Full - flow control rx/tx
Sun Feb 12 02:19:27 2023 daemon.notice netifd: Network device 'wan' link is down
Sun Feb 12 02:19:27 2023 daemon.notice netifd: Interface 'wan' has link connectivity loss
Sun Feb 12 02:19:27 2023 kern.info kernel: [1817980.616018] mv88e6085 f1072004.mdio-mii:00 wan: Link is Down
Sun Feb 12 02:19:31 2023 daemon.notice netifd: Network device 'wan' link is up
Sun Feb 12 02:19:31 2023 daemon.notice netifd: Interface 'wan' has link connectivity
Sun Feb 12 02:19:31 2023 kern.info kernel: [1817984.374982] mv88e6085 f1072004.mdio-mii:00 wan: Link is Up - 1Gbps/Full - flow control rx/tx
Sun Feb 12 02:19:34 2023 daemon.notice netifd: Network device 'wan' link is down
Sun Feb 12 02:19:34 2023 daemon.notice netifd: Interface 'wan' has link connectivity loss
Sun Feb 12 02:19:34 2023 kern.info kernel: [1817987.658451] mv88e6085 f1072004.mdio-mii:00 wan: Link is Down
Sun Feb 12 02:19:40 2023 daemon.notice netifd: Network device 'wan' link is up
Sun Feb 12 02:19:40 2023 daemon.notice netifd: Interface 'wan' has link connectivity
Sun Feb 12 02:19:40 2023 kern.info kernel: [1817993.876098] mv88e6085 f1072004.mdio-mii:00 wan: Link is Up - 1Gbps/Full - flow control rx/tx
Sun Feb 12 02:19:53 2023 daemon.notice netifd: Network device 'wan' link is down
Sun Feb 12 02:19:53 2023 daemon.notice netifd: Interface 'wan' has link connectivity loss
Sun Feb 12 02:19:53 2023 kern.info kernel: [1818006.384620] mv88e6085 f1072004.mdio-mii:00 wan: Link is Down
Sun Feb 12 02:19:59 2023 daemon.notice netifd: Network device 'wan' link is up
Sun Feb 12 02:19:59 2023 daemon.notice netifd: Interface 'wan' has link connectivity
Sun Feb 12 02:19:59 2023 kern.info kernel: [1818012.474463] mv88e6085 f1072004.mdio-mii:00 wan: Link is Up - 1Gbps/Full - flow control rx/tx

And looks like the Hub 4 possibly rebooted as the uptime is:

System up time : 2 days 16h:14m:38s

Though I do see those port type flapping occur even when the there is no reboot of the Hub 4.

Would like to know why it is rebooting also? Just does not seem to be as stable as it used to be.

[jem101]

---

@liquidkool wrote:

When you put the hub in modem mode you can only use one port (port 1)

I have already had the hub replaced, and still getting the issue. Sometimes I see the port flap other times I see complete timeouts on the monitoring I have running constantly. Also notice it when working from home and it freezes up for about 30 seconds. 

something is just not right on the virgin network. 

---

Actually you can use any of them, just one at a time - the 'it has to be port 1' used to be the case for earlier hubs, and I'm not entirely sure it was ever really true, just one of those accepted, received wisdom, sort of things.

So, as an experiment, switch the connection to a different port on the VM hub, you'll probably need to reboot it, and see if you still get the same issues. There have been multiple reports on here from people saying that the ethernet ports on the hubs can be 'a little flaky', shall we say. Personally, I don't think there is anything wrong with your connection per se, but the hub needs replacing, again, I suspect there has been a whole batch of these things produced with, well, not entirely 'Apple' level of quality testing, and you have been unfortunate enough to have been given two of them!

John

[Roger_Gooner]

The power levels on the upstream channels are on the high side, if they go much higher a channel or two might get knocked out.

[Zoie_P]

Hi @liquidkool, thank you for your post 😊

I am sorry to see you are having some issues with your service.

I can see our community helped out on this for you.

Thank you @Roger_Gooner for your advice, there are some issues with these levels that will need a tech, I will pop you over a PM, just keep an eye out for the purple envelope 📩

Thanks, 

Zoie

[Zoie_P]

Thank you for messaging with me @liquidkool 🌞 

I am glad we were able to book a tech to come take a look at your power levels.

Please keep us posted on how your visit goes and how your service is afterwards. You can view or check your appointment here 👉MyVM 📅

Thanks, 

Zoie