U

Visitor

 • 

5 Messages

Thu, Sep 2, 2021 2:39 PM

Intermittent disconnects through the day.

I moved to a new home back in December and since then, my internet has been awful. I'm getting random disconnects throughout the day which some lasts a few seconds but sometimes it can go for minutes. This might not seem like a big deal but when you're working from home joining Zoom meetings all day with customers and getting disconnected constantly, it ends up being very nerve racking as my job depends on my internet reliability.

Enough said, I tried contacting customer service already in the past, a tech was sent out and no signal issues were detected with splitters and without splitters. I tried three different modems and the issues persisted with all of them. (Arris SB6141, Arris S33 and Netgear C6300)

Going through the logs of the modem, I noticed that I'm getting flooded with DoS attacks to my public IP in which I contact Xfinity's support but didn't get anywhere. All they ask is to reboot the modem and run some type of analyzes on the back end which obviously doesn't really do anything:

[DoS attack] ICMP Flood from 45.79.163.228

1

Thursday, 02 Sep 2021 09:22:25

[DoS attack] ICMP Flood from 50.116.10.136

1

Thursday, 02 Sep 2021 09:20:47

[DoS attack] ICMP Flood from 192.53.162.8

1

Thursday, 02 Sep 2021 09:15:27

[DoS attack] ICMP Flood from 45.79.163.228

1

Thursday, 02 Sep 2021 09:12:25

[DoS attack] ICMP Flood from 50.116.10.136

1

Thursday, 02 Sep 2021 09:10:47

At 9:02AM, I got disconnected. See below:

Sep 02 2021 09:17:55 Critical (3) No Ranging Response received - T3 time-out
Sep 02 2021 09:17:54 Critical (3) Unicast Ranging Received Abort Response - initializing MAC
Sep 02 2021 09:17:15 Critical (3) No Ranging Response received - T3 time-out
Sep 02 2021 09:17:15 Critical (3) Unicast Ranging Received Abort Response - initializing MAC
Sep 02 2021 09:06:36 Critical (3) No Ranging Response received - T3 time-out
Sep 02 2021 09:06:36 Critical (3) Unicast Ranging Received Abort Response - initializing MAC
Sep 02 2021 09:02:35 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out
Sep 02 2021 09:02:34 Warning (5) MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Sep 02 2021 09:02:02 Critical (3) No Ranging Response received - T3 time-out
Sep 02 2021 09:02:02 Critical (3) Unicast Ranging Received Abort Response - initializing MAC
Sep 02 2021 09:02:02 Critical (3) Unicast Ranging Received Abort Response - initializing MAC
Sep 02 2021 09:02:02 Critical (3) Unicast Ranging Received Abort Response - initializing MAC
Sep 02 2021 09:02:02 Critical (3) Unicast Ranging Received Abort Response - initializing MAC
Sep 02 2021 09:02:02 Critical (3) Unicast Ranging Received Abort Response - initializing MAC
Sep 02 2021 09:02:02 Critical (3) Unicast Ranging Received Abort Response - initializing MAC
Sep 02 2021 09:02:02 Critical (3) Unicast Ranging Received Abort Response - initializing MAC
Sep 02 2021 09:02:02 Critical (3) Unicast Ranging Received Abort Response - initializing MAC
Sep 02 2021 09:02:02 Critical (3) Unicast Ranging Received Abort Response - initializing MAC

As stated, an Xfinity tech has already been sent out in the past who blamed my modem for being faulty, but again, I tried three different modems and have the same issues with all of them. They seem to have ran 3-4 new coax from the street to the house which I'm guessing this could have been an issue prior to us moving to this new house. The tech did check the splitters and didn't find any issues.

At my previous condo which is 5 blocks from where I currently live, I had no issues.

I'm at the point that I'm considering trying a different provider (At&t Fiber) as I can't seem to reach anyone on Xfinitys side that will assist and resolve this issue once in for all. This post is not to complain as I've been an Xfinity customer for a long time and the service has always been reliable in the past. I'm simply looking for assistance and resolution on getting this fixed.

Thank you.

Responses

Visitor

 • 

5 Messages

1 m ago

I have the same exact issue, minus the DDoS attacks. Exactly the same. Had a tech come out, he replaced the cable going to our house, but no improvement. Similar messages on my modem to yours:

Xfinity is the only provider in my neighborhood so I am quite stuck here until Xfinity finds a way to fix this issue once and for all, but it's very difficult to reach any help.

EG

Expert

 • 

89.6K Messages

1 m ago

@user_601517 

Please also post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.

Visitor

 • 

5 Messages

1 m ago

@EG not sure if you can help me as well at all, but here's the info I have from my modem:

Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables UnCorrectables
1 Locked QAM 256 13 477000000 Hz 2.5 dBmV 38.9 dB 17491 122306
2 Locked QAM 256 14 483000000 Hz 2.9 dBmV 38.6 dB 15686 109404
3 Locked QAM 256 15 489000000 Hz 2.7 dBmV 38.9 dB 16164 102315
4 Locked QAM 256 16 495000000 Hz 3.2 dBmV 38.9 dB 14488 102434
5 Locked QAM 256 17 507000000 Hz 3.7 dBmV 38.6 dB 14440 95048
6 Locked QAM 256 18 513000000 Hz 3.5 dBmV 38.9 dB 14276 83390
7 Locked QAM 256 19 519000000 Hz 3.7 dBmV 38.6 dB 12176 94804
8 Locked QAM 256 20 525000000 Hz 3.4 dBmV 38.6 dB 12934 89775
9 Locked QAM 256 21 531000000 Hz 3.0 dBmV 38.6 dB 12320 82963
10 Locked QAM 256 22 537000000 Hz 2.7 dBmV 38.9 dB 11848 83930
11 Locked QAM 256 23 543000000 Hz 2.7 dBmV 38.6 dB 13253 81778
12 Locked QAM 256 24 549000000 Hz 2.5 dBmV 38.6 dB 11713 79713
13 Locked QAM 256 25 555000000 Hz 2.7 dBmV 38.6 dB 12790 84244
14 Locked QAM 256 26 561000000 Hz 2.9 dBmV 38.6 dB 12554 82174
15 Locked QAM 256 27 567000000 Hz 3.0 dBmV 38.6 dB 11528 80580
16 Locked QAM 256 28 573000000 Hz 3.7 dBmV 38.9 dB 14012 100054
17 Locked QAM 256 29 579000000 Hz 4.4 dBmV 38.9 dB 11278 80904
18 Locked QAM 256 30 585000000 Hz 5.0 dBmV 38.9 dB 12612 82789
19 Locked QAM 256 31 591000000 Hz 5.4 dBmV 38.6 dB 12552 85675
20 Locked QAM 256 32 597000000 Hz 5.8 dBmV 38.9 dB 13282 89765
21 Locked QAM 256 33 603000000 Hz 5.4 dBmV 38.6 dB 13977 89538
22 Locked QAM 256 34 609000000 Hz 5.0 dBmV 38.6 dB 14906 97782
23 Locked QAM 256 35 615000000 Hz 4.5 dBmV 38.6 dB 15605 101349
24 Locked QAM 256 36 621000000 Hz 4.1 dBmV 38.6 dB 12388 93748
25 Locked QAM 256 37 627000000 Hz 3.9 dBmV 38.2 dB 880 10538
26 Locked QAM 256 38 633000000 Hz 3.7 dBmV 38.2 dB 899 11133
27 Locked QAM 256 39 639000000 Hz 3.7 dBmV 38.2 dB 808 10737
28 Locked QAM 256 40 645000000 Hz 3.9 dBmV 38.6 dB 947 10393
29 Locked QAM 256 41 651000000 Hz 4.4 dBmV 38.6 dB 980 10914
30 Locked QAM 256 42 657000000 Hz 4.8 dBmV 39.2 dB 662 11457
31 Locked QAM 256 43 663000000 Hz 5.5 dBmV 38.6 dB 883 12856
32 Locked QAM 256 44 669000000 Hz 5.8 dBmV 39.2 dB 1091 10456

Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 4 5120 Ksym/sec 16400000 Hz 50.0 dBmV
2 Locked ATDMA 3 5120 Ksym/sec 22800000 Hz 49.5 dBmV
3 Locked ATDMA 2 5120 Ksym/sec 29200000 Hz 49.3 dBmV
4 Locked ATDMA 1 5120 Ksym/sec 35600000 Hz 49.5 dBmV
5 Locked ATDMA 5 1280 Ksym/sec 39600000 Hz 47.3 dBmV
6 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV
7 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV
8 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV

Time Priority Description
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:25:58 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
Sep 01 2021 15:26:22 Critical (3) No Ranging Response received - T3 time-out
Sep 01 2021 15:47:30 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:47:30 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
Sep 01 2021 15:47:31 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:47:31 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
Sep 01 2021 15:47:35 Critical (3) No Ranging Response received - T3 time-out
Sep 01 2021 15:48:41 Critical (3) SYNC Timing Synchronization failure - Loss of Sync
Sep 01 2021 15:48:42 Critical (3) No Ranging Response received - T3 time-out
Sep 01 2021 15:54:18 Critical (3) SYNC Timing Synchronization failure - Loss of Sync
Sep 01 2021 15:54:19 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:54:19 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
Sep 01 2021 15:54:19 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 15:54:19 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
Sep 01 2021 15:54:43 Critical (3) No Ranging Response received - T3 time-out
Sep 01 2021 15:57:09 Critical (3) SYNC Timing Synchronization failure - Loss of Sync
Sep 01 2021 15:57:31 Critical (3) No Ranging Response received - T3 time-out
Sep 01 2021 16:01:07 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 16:01:07 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
Sep 01 2021 16:01:07 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 16:01:07 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
Sep 01 2021 16:01:31 Critical (3) No Ranging Response received - T3 time-out
Sep 01 2021 16:07:56 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 16:07:56 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
Sep 01 2021 16:07:56 Critical (3) Ranging Request Retries exhausted
Sep 01 2021 16:07:56 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
Sep 01 2021 16:08:20 Critical (3) No Ranging Response received - T3 time-out
Sep 02 2021 05:41:55 Warning (5) Lost MDD Timeout
Sep 02 2021 05:46:40 Critical (3) No Ranging Response received - T3 time-out
Sep 02 2021 05:47:23 Critical (3) Ranging Request Retries exhausted
Sep 02 2021 05:47:23 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
Sep 02 2021 05:47:47 Critical (3) No Ranging Response received - T3 time-out
Sep 02 2021 10:12:58 Critical (3) Ranging Request Retries exhausted
Sep 02 2021 10:12:58 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
Sep 02 2021 10:13:14 Critical (3) Ranging Request Retries exhausted
Sep 02 2021 10:13:14 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
Sep 02 2021 10:13:20 Critical (3) Ranging Request Retries exhausted
Sep 02 2021 10:13:20 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
Sep 02 2021 10:13:22 Critical (3) No Ranging Response received - T3 time-out
EG

Expert

 • 

89.6K Messages

@user_ec70f3

Please create a new topic of your own here on this board detailing your issue and I will attempt to assist you there (copy your post and paste it there). Please do not hijack someone else's help thread in progress. Thank you.
 

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer!tick

Visitor

 • 

5 Messages

@EG Not trying to hijack anyone else's thread, just thought it made sense to put info about a similar issue on the same topic. I will make a new thread though.

EG

Expert

 • 

89.6K Messages

No prob. I see a problem with your stats but I can't advise you in this thread. Multiple posters piling on to and being helped in a single thread becomes too complicated. confusing, and convoluted. And it's unfair to the original poster.

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer!tick

Visitor

 • 

5 Messages

@EG Thank you so much for taking the time to help me. Here is the info requested (Original Poster) :

Frequency start Value
This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.
Starting Frequency

<tabindex=-1>Startup Procedure</tabindex=-1>
Procedure Status Comment
Acquire Downstream Channel 669000000 Hz Locked
Connectivity State Ok Operational
Boot State Ok Operational
Security Enabled BPI+
IP Provisioning Mode Honor MDD honorMdd(4)

Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables UnCorrectables
1 Locked QAM 256 29 573000000 Hz 1.7 dBmV 40.9 dB 253 1136
2 Locked QAM 256 30 579000000 Hz 1.7 dBmV 40.9 dB 488 3031
3 Locked QAM 256 31 585000000 Hz 1.2 dBmV 40.9 dB 208 1060
4 Locked QAM 256 32 591000000 Hz 1.7 dBmV 40.3 dB 87 140
5 Locked QAM 256 33 597000000 Hz 2.0 dBmV 38.6 dB 111 172
6 Locked QAM 256 34 603000000 Hz 1.7 dBmV 38.9 dB 287 2225
7 Locked QAM 256 35 609000000 Hz 1.4 dBmV 40.3 dB 216 1181
8 Locked QAM 256 36 615000000 Hz 1.0 dBmV 40.3 dB 87 113
9 Locked QAM 256 37 621000000 Hz 1.2 dBmV 40.9 dB 79 220
10 Locked QAM 256 38 627000000 Hz 1.4 dBmV 40.3 dB 368 2135
11 Locked QAM 256 39 639000000 Hz 1.0 dBmV 39.8 dB 202 1175
12 Locked QAM 256 40 645000000 Hz 1.0 dBmV 40.9 dB 126 85
13 Locked QAM 256 41 651000000 Hz 0.9 dBmV 40.9 dB 479 893
14 Locked QAM 256 42 657000000 Hz 0.9 dBmV 40.3 dB 464 4050
15 Locked QAM 256 43 663000000 Hz 1.0 dBmV 40.3 dB 362 2113
16 Locked QAM 256 44 669000000 Hz 1.0 dBmV 40.9 dB 101 88

Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 4 5120 Ksym/sec 16400000 Hz 51.0 dBmV
2 Locked ATDMA 3 5120 Ksym/sec 22800000 Hz 51.0 dBmV
3 Locked ATDMA 2 5120 Ksym/sec 29200000 Hz 51.0 dBmV
4 Locked ATDMA 1 5120 Ksym/sec 35600000 Hz 51.0 dBmV

Current System Time: Thu Sep 2 14:04:46 2021
System Up Time: 03:57:23

(edited)

EG

Expert

 • 

89.6K Messages

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 !

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer!tick

Visitor

 • 

2 Messages

1 m ago

same issue...intermittent disconnects all day long...some days it's not bad but some days it's just awful....need some help Comcast!

This comment has been converted into a post

Official Employee

 • 

367 Messages

1 m ago

Hi there! We would be happy to assist you. Can you initiate a chat and start with your full name and address? To start a chat, please click the chat icon in the top right of the page! Search for Xfinity Support, if needed. Talk to you there! 

This comment was created from this reply
This comment has been converted into a post

New to the Community?

Start Here