XB7 Frequently Loses Internet

1200 down/40 up plan. XB7 gateway.

Over the past few months, ever since moving and upgrading to XB7 my home network has been repeatedly 'crashing' multiple times each day. The WiFi stays up but the internet connection is lost for about 8-10 minutes each time. Also during this window the TV box resets. Here are the troubleshooting steps I have taken so far with no luck resolving the issue:

Disconnected and reconnected all indoor cables
Disconnected all but one device for testing
Disconnected the TV box
Disabled Xfinity Hotspot
Disabled IPv6
Disabled Advanced Security
Separated the WiFi networks (2.4GHz and 5GHz instead of both combined)
Tried all levels of the Firewall
Many resets and reboots

I work from home and my kids school from home full-time. This issue is severely impacting both. What are the next steps at this point? Should I get a replacement gateway?

Here are my Downstream stats:

Downstream	Channel Bonding Value
Index	5	2	3	4	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31	32	37
Lock Status	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked
Frequency	507 MHz	483 MHz	489 MHz	495 MHz	513 MHz	519 MHz	525 MHz	531 MHz	537 MHz	543 MHz	549 MHz	555 MHz	561 MHz	567 MHz	573 MHz	579 MHz	585 MHz	591 MHz	597 MHz	603 MHz	609 MHz	615 MHz	621 MHz	627 MHz	633 MHz	639 MHz	645 MHz	651 MHz	657 MHz	663 MHz	669 MHz	690000000
SNR	41.1 dB	41.1 dB	40.9 dB	40.9 dB	41.2 dB	41.2 dB	41.0 dB	41.2 dB	41.1 dB	41.1 dB	40.9 dB	41.0 dB	41.2 dB	41.3 dB	41.1 dB	41.0 dB	40.9 dB	41.0 dB	41.2 dB	40.9 dB	41.0 dB	40.9 dB	41.1 dB	41.1 dB	40.7 dB	40.9 dB	41.0 dB	41.0 dB	41.0 dB	41.1 dB	40.8 dB	40.9 dB
Power Level	-1.3 dBmV	-1.3 dBmV	-1.5 dBmV	-1.8 dBmV	-1.3 dBmV	-1.6 dBmV	-1.6 dBmV	-1.3 dBmV	-1.2 dBmV	-1.5 dBmV	-1.5 dBmV	-1.3 dBmV	0.7 dBmV	0.5 dBmV	0.9 dBmV	0.9 dBmV	0.9 dBmV	0.6 dBmV	0.4 dBmV	-1.0 dBmV	0.9 dBmV	0.9 dBmV	0.5 dBmV	0.6 dBmV	0.7 dBmV	-1.0 dBmV	-1.0 dBmV	0.7 dBmV	0.9 dBmV	0.9 dBmV	-1.6 dBmV	0.6 dBmV
Modulation	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	OFDM

Here are my Upstream stats:

Upstream	Channel Bonding Value
Index	1	2	3	4	5
Lock Status	Locked	Locked	Locked	Locked	Locked
Frequency	35 MHz	29 MHz	22 MHz	16 MHz	39 MHz
Symbol Rate	5120	5120	5120	5120	1280
Power Level	51.5 dBmV	51.8 dBmV	51.3 dBmV	51.3 dBmV	51.3 dBmV
Modulation	QAM	QAM	QAM	QAM	QAM
Channel Type	ATDMA	ATDMA	ATDMA	ATDMA	ATDMA

Finally the CM Error stats:

CM Error Codewords
Index	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31	32
Unerrored Codewords	352765759	3645814310	3645853744	3645950331	3646024666	3646110080	3646189755	3646264092	3646362253	3646437133	3646518520	3646581999	3646664170	3646745117	3646846363	3646904343	3519079116	3519176685	3519251099	3519305348	3519339846	3519369045	3519438085	3366186489	3519391778	3519510986	3519585225	3519640186	3519706877	3519815366	3519890278	352765759
Correctable Codewords	311011620	27015	27723	30789	31721	27101	29562	27655	25014	23532	26113	28319	26890	24338	23358	26305	26993	25690	24132	29189	31793	34106	29015	32522	32696	29485	29508	32703	34255	31275	28247	311011620
Uncorrectable Codewords	576260	47412	55471	64343	59974	52607	60432	54931	44444	41018	52052	57883	53404	43426	40916	49710	54041	49630	41370	60854	71205	68588	54922	83772	81370	69077	70443	81492	81284	67929	56610	576260

There is nothing in the System or Event logs, but here is my Firewall log for the past week (MACs removed):

FW.IPv6 FORWARD drop , 553 Attempts, 2022/1/14 00:24:33	Firewall Blocked
FW.IPv6 INPUT drop , 42396 Attempts, 2022/1/14 00:24:33	Firewall Blocked
FW.IPv6 FORWARD drop , 3280 Attempts, 2022/1/13 18:58:00	Firewall Blocked
FW.IPv6 INPUT drop , 247530 Attempts, 2022/1/13 18:58:00	Firewall Blocked
Device MAC:xxx , 701 Attempts, 2022/1/13 08:00:00	Device Blocked
Device MAC:xxx , 41 Attempts, 2022/1/13 08:00:00	Device Blocked
FW.WANATTACK DROP , 33 Attempts, 2022/1/13 04:58:00	Firewall Blocked
FW.IPv6 FORWARD drop , 2221 Attempts, 2022/1/12 18:58:00	Firewall Blocked
FW.IPv6 INPUT drop , 215153 Attempts, 2022/1/12 18:58:00	Firewall Blocked
Device MAC:xxx , 926 Attempts, 2022/1/12 08:00:00	Device Blocked
Device MAC:xxx , 829 Attempts, 2022/1/12 08:00:00	Device Blocked
FW.IPv6 FORWARD drop , 842 Attempts, 2022/1/11 18:58:00	Firewall Blocked
FW.IPv6 INPUT drop , 208703 Attempts, 2022/1/11 18:58:00	Firewall Blocked
Device MAC:xxx , 474 Attempts, 2022/1/11 08:00:00	Device Blocked
Device MAC:xxx , 336 Attempts, 2022/1/10 22:58:00	Device Blocked
FW.IPv6 INPUT drop , 214936 Attempts, 2022/1/10 18:58:00	Firewall Blocked
FW.IPv6 FORWARD drop , 112 Attempts, 2022/1/10 18:58:00	Firewall Blocked
FW.WANATTACK DROP , 2 Attempts, 2022/1/10 17:58:00	Firewall Blocked
Device MAC:xxx , 71 Attempts, 2022/1/9 22:58:01	Device Blocked
FW.IPv6 INPUT drop , 218513 Attempts, 2022/1/9 18:58:00	Firewall Blocked

Responses

EG

Expert

•

110K Messages

3 years ago

The upstream power is too high and it may be intermittently fluctuating even higher out of spec. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.

In an effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1000 MHz, bi-directional, and no gold colored garbage from Radio Shack, Home Depot, Target, etc. Splitters should be swapped with known to be good / new ones to test.

Also check the coax cable for any damage such as cuts, nicks, kinks, sharp bends, etc.

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two-way splitter connected directly off of the drop from the street / pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.

Good luck with it !

1

R

ReliC426

Visitor

•

2 Messages

@EG

Thanks for the response.

My setup is quite simple: only one coax jack is active in the house, I have a cable coming from that jack into a single splitter that then goes to the gateway and to the TV box. That's it. The cables and splitter used were the ones provided by Comcast. However, I did not inspect them very closely during my troubleshooting and had merely reconnected them. I will check for/clean any corrosion and will inspect the entire length of the cables (rather short) for any damage or kinks. As an additional troubleshooting step I will completely remove the splitter and TV box and simply run the cable from the wall jack to the gateway and see if I still experience issues.

Again, thank you!

3 years ago

0

EG

Expert

•

110K Messages

3 years ago

You're welcome ! If nothing applies then you'll need to get a tech out as stated.

Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home.

Good luck !

0

Your Home Network

ReliC426

XB7 Frequently Loses Internet

EG

ReliC426

EG

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