U

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2 Messages

Wednesday, June 28th, 2023 10:43 PM

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IPV 6 / Lan Continuous Drops without explanation

I cant take the <Edited: Language> anymore from customer support and I am really hoping someone who experienced the same issue I am has a fix they found. For over a year now I have been experiencing almost daily if not 3-4 times weekly were my router/modem will continuously reset it self due to IPV 6 and Lan drops from the firewall, sometimes it last for minutes sometimes its hours. I have had over 6 techs come out to replace lines, modems, add/remove splitters, work on the outside box as well as replaced old grounding wires. Nothing works. Once my job moved to hybrid scheduling and I am working from home more then 20 hours a week it is now effecting my job which I wont have. I have since filed 2 BBB complaints, talked to their security team ( who is a joke) and no one has ever provided a resolution nor even acknowledge the fact this is a issue multiple customers are experiencing. I have combed these forums, reedit and cant seem to find an answer. I have currently put my modem into bridge mode while using my own netgear router. I am getting the same errors seen all over the forums fw.lan2self drop and FW.IPv6 INPUT drop. This causes the modem to reboot over and over again. I just recently had the newest modem put in by a tech and the issue of course is still continuing. Please anyone out there who has a fix even if I have to out of pocket I cant continue to have this happen. Unfortunately I live in a condo complex and Xfinity had a contract with them so i cant even switch to Verizon which I prefer to do.

I have 1 hard wired PC, hard wired smart tv, 2 phones on wifi and my work laptop. I have ran scans, checked all devices for spyware / malicious software and nothing. 


Hours on hold with customer service does nothing as they just send another tech out who have no idea what the issue is or how to fix.

Problem Solver

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1.5K Messages

2 years ago

Firewall messages are just that.  Firewall messages.  They're poorly documented on consumer modems, if at all.  If you have an actual firewall, you'll get more detail if you want, likely they are rules you wrote so you know what they are associated with, but mostly, it's just stray botnet traffic/compromised cloud servers banging IP addresses on Xfinity's network, and hijacked grandma machines running windows 7 portscanning other customers for something to exploit.

If you've got a bad signal coming in from the street, you've got zero chance.  If you've got bad wiring/splitters in your house, you've equally got zero chance of your modem/gateway working.  Downstream power too high drops channels and causes reboots sometimes, upstream power pushing too much trying to get through bad connectors/cables/splitters also causes reboots.  My Netgear will tip over if the outbound pushes past 55 dBmV.

Signal power will change over time too.  Might look fine/marginal enough when they look at it.  It might not later in the day.  

Take a look here.  See if anything applies.  https://forums.xfinity.com/conversations/your-home-network/internet-troubleshooting-tips/602dae4ac5375f08cde52ea0 

Visitor

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2 Messages

@flatlander3​ Here is what I pulled directly from the modem. From my understanding every tech that has come out had tested the signal to my condo, to my home and I have been told multiple times everything is exactly where it should be. Not I don't fully understand these logs so maybe someone can help out.  

Down

Channel ID
42
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
30
31
32
33
34
35
36
37
38
39
40
41
43
44
45
29
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
669 MHz
507 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
675 MHz
681 MHz
687 MHz
693000000
SNR
43.7 dB
43.4 dB
43.4 dB
43.4 dB
43.4 dB
43.4 dB
43.6 dB
43.5 dB
43.7 dB
43.6 dB
43.5 dB
43.6 dB
43.5 dB
43.6 dB
43.4 dB
43.5 dB
43.4 dB
43.6 dB
43.5 dB
43.5 dB
43.5 dB
43.5 dB
43.6 dB
43.6 dB
43.9 dB
43.8 dB
43.7 dB
43.7 dB
43.0 dB
44.0 dB
43.9 dB
43.5 dB
Power Level
8.8 dBmV
7.0 dBmV
7.2 dBmV
7.1 dBmV
7.1 dBmV
7.3 dBmV
7.5 dBmV
7.7 dBmV
7.9 dBmV
7.7 dBmV
7.6 dBmV
8.0 dBmV
7.7 dBmV
7.9 dBmV
7.6 dBmV
7.8 dBmV
7.9 dBmV
8.2 dBmV
8.2 dBmV
8.3 dBmV
8.4 dBmV
8.4 dBmV
8.5 dBmV
8.6 dBmV
8.9 dBmV
8.8 dBmV
8.6 dBmV
8.7 dBmV
9.0 dBmV
9.3 dBmV
9.0 dBmV
8.9 dBmV
Modulation
256 QAM
256 QAM
256 QAM
256 QAM
256 QAM

Up

Upstream
Channel Bonding Value
Channel ID
65
66
67
68
Lock Status
Locked
Locked
Locked
Locked
Frequency
16 MHz
22 MHz
29 MHz
35 MHz
Symbol Rate
5120
5120
5120
5120
Power Level
41.0 dBmV
41.0 dBmV
41.0 dBmV
40.0 dBmV
Modulation
QAM
QAM
QAM
QAM
Channel Type
ATDMA
ATDMA
ATDMA
ATDMA

FW.IPv6 INPUT drop , 523 Attempts, 2023/6/28 18:53:35 Firewall Blocked
FW.IPv6 FORWARD drop , 7 Attempts, 2023/6/28 17:58:00 Firewall Blocked

Problem Solver

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1.5K Messages

2 years ago

Upstream is good.  Downstream is drifting high out of spec.   That one doesn't tell you uncorrectable errors to see if it's a problem or not at that level, but it usually isn't helpful to run out of spec -- if that's a gateway in bridge mode.  You might want to look at it in a few hours, and  especially if you notice any stalls or lags or if that increases more, and after it's been up longer -- judging by your firewall hits.  Past 7dBmV isn't going to help you on a gateway.  Can you get away with 10dBmV on a straight modem these days?  Meh....maybe.  Maybe not. 

Are you picking up a bunch of errors in the error log?  You'd have to redact the CM MAC and MAC addresses if you post them or the bot will mark your post private (confidential information). 

If that's a clean run directly to the modem/gateway (no splitters), there's a frequency dependent reflection.  That could be just a connector.  It's not much of a signal tilt, but it is desirable not to have those, and have every signal within a dBmV.   You can try taking the connectors apart.  Shine up the center copper.  Likely it won't fix that, and it won't fix a  reboot issue but it can't hurt.  It might be coming from the street too and there's nothing you can do about it.

If there is a splitter, try running without it, see if signal power does then for a test.  It's usually better not to have them at all.  Downstream may go up a lot.

For that, you can try one of these for $11:  https://amazon.com/FPA6-54-Fodesireablerward-Attenuator-DOCSIS-Internet/dp/B08KTRC3XZ 

I was drifting high after they "fixed the cable" in the neighborhood and installed one to knock the signal back down into spec.  Can even go on the back of a modem/gateway.  It reduces downstream power, and does not do anything with upstream.  If it works, great.  If it doesn't, you're out $11.  

This RF stuff can be really touchy, the consumer gear is cost reduced junk, and also pretty twitchy on it's own.  If they can't do anything with it, it might be up to you to mess with it.  It's what I had to do.

(edited)

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