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Connectivity issues, constant internet drop out issues

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New Poster

Connectivity issues, constant internet drop out issues

I've been seeing these in my syslogs when I lose conectivity

 

kernel: rndbr1: received packet on l2sd0.2 with own address as source address

kernel: mroute: pending queue full, dropping entries 

 

and these:

 

2020-09-14 10:03:25 [CRITICAL] Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
2020-09-14 10:09:41 [WARNING] MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
2020-09-14 10:10:42 [CRITICAL] SYNC Timing Synchronization failure - Loss of Sync
2020-09-14 11:15:59 [WARNING] MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
2020-09-15 00:40:54 [CRITICAL] No Ranging Response received - T3 time-out
2020-09-22 19:06:13 [WARNING] Lost MDD Timeout
2020-09-23 06:38:26 [CRITICAL] No Ranging Response received - T3 time-out
2020-09-23 07:23:34 [WARNING] Lost MDD Timeout

 

 

Hardware: ASUS Ac2600 CM and WIFI router 

 

here is CM stats:

Upstream Major Frequency

Upstream
23700 KHz

Downstream Major Frequency

Downstream
615000 KHz
Starting Frequency  KHz 

Transmitter # Channel ID Lock Status Frequency Modulation Symbol Rate Channel Type Power

Upstream Channel Status
1
2
Locked
23700000
64 QAM
5120000
ATDMA
51.00 dBmV
2
4
Locked
36500000
64 QAM
5120000
ATDMA
51.00 dBmV
3
3
Locked
30100000
64 QAM
5120000
ATDMA
51.00 dBmV
4
1
Locked
17300000
64 QAM
5120000
ATDMA
51.00 dBmV
0
---
Unlocked
0
---
---
---
---
0
---
Unlocked
0
---
---
---
---
0
---
Unlocked
0
---
---
---
---
0
---
Unlocked
0
---
---
---
---

Receiver # Channel ID Lock Status Frequency Modulation Symbol Rate SNR Power

Downstream Channel Status
1
1(Prm)
Locked
615000000
256 QAM
5360000
37.636 dB
-1.40 dBmV
2
2
Locked
459000000
256 QAM
5360000
38.983 dB
-0.70 dBmV
3
3
Locked
465000000
256 QAM
5360000
38.605 dB
-0.90 dBmV
4
4
Locked
471000000
256 QAM
5360000
38.605 dB
-0.70 dBmV
5
5
Locked
477000000
256 QAM
5360000
38.605 dB
-0.60 dBmV
6
6
Locked
483000000
256 QAM
5360000
38.605 dB
-0.60 dBmV
7
7
Locked
489000000
256 QAM
5360000
38.605 dB
-0.70 dBmV
8
8
Locked
495000000
256 QAM
5360000
38.605 dB
-0.90 dBmV
9
9
Locked
507000000
256 QAM
5360000
38.605 dB
-1.10 dBmV
10
10
Locked
513000000
256 QAM
5360000
38.605 dB
-1.10 dBmV
11
11
Locked
519000000
256 QAM
5360000
37.636 dB
-1.00 dBmV
12
12
Locked
525000000
256 QAM
5360000
38.605 dB
-0.90 dBmV
13
13
Locked
531000000
256 QAM
5360000
38.605 dB
-1.00 dBmV
14
14
Locked
543000000
256 QAM
5360000
37.636 dB
-1.40 dBmV
15
15
Locked
549000000
256 QAM
5360000
37.356 dB
-1.60 dBmV
16
16
Locked
555000000
256 QAM
5360000
37.356 dB
-1.90 dBmV
17
17
Locked
561000000
256 QAM
5360000
37.636 dB
-1.70 dBmV
18
18
Locked
567000000
256 QAM
5360000
37.636 dB
-1.80 dBmV
19
19
Locked
573000000
256 QAM
5360000
37.636 dB
-1.70 dBmV
20
20
Locked
579000000
256 QAM
5360000
37.356 dB
-1.90 dBmV
21
21
Locked
585000000
256 QAM
5360000
32.963 dB
-1.90 dBmV
22
22
Locked
591000000
256 QAM
5360000
32.237 dB
-2.10 dBmV
23
23
Locked
597000000
256 QAM
5360000
36.610 dB
-2.20 dBmV
24
24
Locked
603000000
256 QAM
5360000
37.356 dB
-2.10 dBmV
25
25
Locked
609000000
256 QAM
5360000
37.300 dB
-1.70 dBmV
26
26
Locked
621000000
256 QAM
5360000
37.300 dB
-1.40 dBmV
27
27
Locked
627000000
256 QAM
5360000
36.900 dB
-1.40 dBmV
28
28
Locked
633000000
256 QAM
5360000
36.900 dB
-1.70 dBmV
29
29
Locked
639000000
256 QAM
5360000
36.900 dB
-1.40 dBmV
30
30
Locked
645000000
256 QAM
5360000
36.900 dB
-1.80 dBmV
31
31
Locked
651000000
256 QAM
5360000
36.900 dB
-1.80 dBmV
32
32
Locked
657000000
256 QAM
5360000
36.400 dB
-1.70 dBmV
 
 
 
 
 
 
 
 
 
 
Highlighted
Expert

Re: Connectivity issues, constant internet drop out issues

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 a self troubleshooting 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 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

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.



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New Poster

Re: Connectivity issues, constant internet drop out issues

my one splitter is a 3 way splitter from IDEAL with a power pass.   the power pass was conencted to my cable box, and i switched it to my modem/router. 

 

my power lvl is now 49, and my SNR levels are about 38.9.

 

I'm going to go investigate using a different splitter, and the wiring outside next. 

Highlighted
Expert

Re: Connectivity issues, constant internet drop out issues

49 is still on the high side. Looks like more work needs to be done. BTW, that splitter is a garbage brand. It is also engineered more for satellite systems than for cable systems. This can actually introduce problems. I posted info on the proper splitters for cable. 

It may not be the root cause of your issue, but I would swap it to anyway. YMMV. Good luck !



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? Mark the post as Best Answer!