Community Forum

Modem Randomly Reboots

Highlighted
Frequent Visitor

Modem Randomly Reboots

Hi, I have a Netgear C7100V. I have an "Home Run" from the ground block (no splitters or anything) to the back of my modem (direct line). On occasion, my modem will reboot randomly. We only have internet and phone. One time, I was home when it happened. I was gaming on line (call of duty) and I was getting weird artifacts & lagging, seen the house phone rang (a weird long ringing). Then the modem reboots. Prior to this, I would randomly lose just the wifi service. I was in a Netgear forum, but no one could help. They only suggested that I contact Comcast and "Have the ISP check the signal and line quality UP to the modem". With this virus (pandemic) I was going to hold off for now, but wanted to reach out here.
I don't know how to read the logs in the modem, perhaps someone here does.
I was fed to churches my wifi channel from auto to 1, 6 or 11 on 2.5ghz. But when I used a wifi Analyzer tool, there was a lot of interference on those channels. The best one SAS changeling 3. So I changed it to that.

Also, below, I removed the MAC & IP addresses. I'll try to she a screenshot on my pc too, if needed.

Event Log:
2020-05-16, 06:25:35.0 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC CMTS-MAC=CM-QOS=1.1;CM-VER=3.0;
2020-05-16, 06:25:10.0 Warning (5) Unicast DSID PSN startup error
2020-05-16, 03:44:36.0 Notice (6) WiFi Interface [wl0] set to Channel 3 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2020-05-16, 03:44:26.0 Notice (6) WiFi Interface [wl0] set to Channel 3 (Side-Band Channel:7) - Reason:GUI
2020-05-15, 14:57:28.0 Warning (5) MDD message timeout;CM-MAC=CMTS-MAC=CM-QOS=1.1;CM-VER=3.0;
2020-05-15, 14:57:28.0 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.0;
2020-05-14, 10:08:39.0 Warning (5) MDD message timeout;CM-MAC=;CMTS-MAC=CM-QOS=1.1;CM-VER=3.0;
2020-05-14, 10:08:39.0 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=CMTS-MAC=CM-QOS=1.1;CM-VER=3.0;
2020-05-11, 12:50:52.0 Warning (5) MDD message timeout;CM-MAC=;CMTS-MAC=CM-QOS=1.1;CM-VER=3.0;
2020-05-11, 12:50:52.0 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.0;
2020-05-11, 02:54:25.0 Notice (6) WiFi Interface [wl0] set to Channel 3 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2020-05-11, 02:54:23.0 Notice (6) WiFi Interface [wl0] set to Channel 3 (Side-Band Channel:7) - Reason:GUI
2020-05-11, 02:51:23.0 Notice (6) WiFi Interface [wl0] set to Channel 1 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2020-05-11, 02:51:21.0 Notice (6) WiFi Interface [wl0] set to Channel 1 (Side-Band Channel:5) - Reason:GUI
2020-05-11, 02:50:13.0 Notice (6) WiFi Interface [wl0] set to Channel 1 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2020-05-11, 02:49:41.0 Warning (5) MDD message timeout;CM-MAC=b0:b9:8a:d3:71:40;CMTS-MAC=18:8b:9d:4a:3d:61;CM-QOS=1.1;CM-VER=3.0;
2020-05-11, 02:47:57.0 Notice (6) WiFi Interface [wl0] set to Channel 4 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2020-05-11, 02:47:53.0 Notice (6) WiFi Interface [wl0] set to Channel 4 (Side-Band Channel:8) - Reason:GUI
2020-05-11, 02:46:29.0 Notice (6) WiFi Interface [wl0] set to Channel 6 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2020-05-11, 02:46:25.0 Notice (6) WiFi Interface [wl0] set to Channel 6 (Side-Band Channel:10) - Reason:GUI
2020-05-11, 02:45:00.0 Notice (6) WiFi Interface [wl0] set to Channel 5 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2020-05-11, 02:44:56.0 Notice (6) WiFi Interface [wl0] set to Channel 5 (Side-Band Channel:9) - Reason:GUI
2020-05-11, 02:34:06.0 Notice (6) WiFi Interface [wl0] set to Channel 3 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2020-05-11, 02:34:03.0 Notice (6) WiFi Interface [wl0] set to Channel 3 (Side-Band Channel:7) - Reason:GUI
2020-05-11, 02:27:13.0 Notice (6) WiFi Interface [wl0] set to Channel 7 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2020-05-11, 02:27:09.0 Notice (6) WiFi Interface [wl0] set to Channel 7 (Side-Band Channel:3) - Reason:GUI
2020-05-11, 02:25:09.0 Notice (6) WiFi Interface [wl0] set to Channel 5 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2020-05-11, 02:25:05.0 Notice (6) WiFi Interface [wl0] set to Channel 5 (Side-Band Channel:9) - Reason:GUI
2020-05-11, 02:22:12.0 Notice (6) WiFi Interface [wl0] set to Channel 6 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2020-05-11, 02:22:08.0 Notice (6) WiFi Interface [wl0] set to Channel 6 (Side-Band Channel:10) - Reason:GUI
2020-05-11, 02:20:32.0 Notice (6) WiFi Interface [wl0] set to Channel 4 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2020-05-11, 02:20:30.0 Notice (6) WiFi Interface [wl0] set to Channel 4 (Side-Band Channel:8) - Reason:GUI
2020-05-11, 02:19:11.0 Notice (6) WiFi Interface [wl0] set to Channel 2 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2020-05-11, 02:19:07.0 Notice (6) WiFi Interface [wl0] set to Channel 2 (Side-Band Channel:6) - Reason:GUI
2020-05-11, 02:17:52.0 Notice (6) WiFi Interface [wl0] set to Channel 11 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2020-05-11, 02:17:48.0 Notice (6) WiFi Interface [wl0] set to Channel 11 (Side-Band Channel:7) - Reason:GUI
2020-05-11, 02:14:00.0 Notice (6) WiFi Interface [wl0] set to Channel 1 (Side-Band Channel:N/A) - Reason:INTERFERENCE
Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6
Time Not Established Notice (6) WiFi Interface [wl0] set to Channel 3 (Side-Band Channel:N/A) - Reason:INIT
Time Not Established Notice (6) WiFi Interface [wl1] set to Channel 36 (Side-Band Channel:N/A) - Reason:INIT


MTA Event Log - I REMOVED IP ADDRESS
Refresh

Time Text EndpointName
2020-05-16 06:26:31 INFO: Endpt 0 on-hook; cmgr event OPER_OK mB0B98AD37141.chlm5.ma.comcast.net/
2020-05-16 06:26:31 INFO: Endpt 0 on-hook; cmgr event TARGETS_UPDATE mB0B98AD37141.chlm5.ma.comcast.net/
2020-05-16 06:26:30 INFO: Endpt 0 on-hook; cmgr event TARGETS_UPDATE mB0B98AD37141.chlm5.ma.comcast.net/
2020-05-16 06:26:30 INFO: Endpt 0 on-hook; cmgr event TARGETS_UPDATE mB0B98AD37141.chlm5.ma.comcast.net/
2020-05-16 06:26:30 INFO: Endpt 0 on-hook; cmgr event TARGETS_UPDATE mB0B98AD37141.chlm5.ma.comcast.net/
2020-05-16 06:26:30 INFO: Endpt 0 on-hook; cmgr event TARGETS_UPDATE mB0B98AD37141.chlm5.ma.comcast.net/
2020-05-16 06:26:26 INFO: Endpt 1 on-hook; cmgr event OPER_NOK_FORBIDDEN mB0B98AD37141.chlm5.ma.comcast.net/
2020-05-16 06:26:26 Registration failed for user <B0B98AD37141002@ims.comcast.net>; reason<port shutdown 403 FORBIDDEN> mB0B98AD37141.chlm5.ma.comcast.net/
2020-05-16 06:26:26 INFO: Endpt 1 on-hook; cmgr event TARGETS_UPDATE mB0B98AD37141.chlm5.ma.comcast.net/
2020-05-16 06:25:44 MEM-CONN-ERROR;No IP address mB0B98AD37141.chlm5.ma.comcast.net/
2020-05-16 06:25:43 Provisioning Complete mB0B98AD37141.chlm5.ma.comcast.net/
Highlighted
Expert

Re: Modem Randomly Reboots

What do the modem's signal stats look like ? Please also post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.




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!
Highlighted
Frequent Visitor

Re: Modem Randomly Reboots

Where do I find them?
As I write this at work in NY. The modem is currently down. I have to go home and unplug it and start it up again. Unless we lost power (it's sunny and 75)but then again, it happens where I live more often than not.. Lol
Highlighted
Expert

Re: Modem Randomly Reboots

1. Launch a web browser from a computer or mobile device that is connected to the
modem router network.
2. Type http://routerlogin.net or http://192.168.0.1.
A login window opens.
3. Enter the modem router user name and password.
The user name is admin. The default password is password. The user name and
password are case-sensitive.
The BASIC Home page displays.
4. Select Cable Connection.
The Startup Procedure section displays the initialization progress. The page also displays
the status of all downstream and upstream channels.(Scroll down to view all the
channels.) The number of downstream and upstream channels that are locked depends
on the number of channels that your Internet provider uses



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!
Highlighted
Frequent Visitor

Re: Modem Randomly Reboots

@EG I copied and pasted this in my original post. It looked garbled..but I did a screen shot now. I just got home and had to unplug it, then plug it back in. 

couldn't upload a picture for some reason, maybe cause it's my first post? so I used Imgur. I hope you can see it. 

 

Cable Connection 

Highlighted
Frequent Visitor

Re: Modem Randomly Reboots

I posted it. It's up 2 posts 👆. After posting, I was able to get Comcast to come out tomorrow.
Highlighted
Most Valued Poster

Re: Modem Randomly Reboots

Your Log shows Wifi interference.

Highlighted
Most Valued Poster

Re: Modem Randomly Reboots

Highlighted
Expert

Re: Modem Randomly Reboots

The downstream power is on the low side and it may be intermittently fluctuating even lower to out of spec levels. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, and latency problems.

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.



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!
Highlighted
Frequent Visitor

Re: Modem Randomly Reboots

@EG 
Thanks!
As I mentioned in my first post, I hate a direct line (Home Run). I have an RG-11 underground from the tap (pedistal) to the side of my house (ground block). That connection is then connected to the line that goes directly to my modem (RG-56 quad shield). At the ground block I did notice, the wire going into my house had a slight bend to it (ALMOST a 90°Angle) which I'm sure doesn't help.

I went to the 4 port tap and found a broken port (not mine, but a neighbors). I fixed his problems he was having.  I get all of what he said, but I don't know how to read the modem info.

https://imgur.com/a/uJcZWAU 

https://imgur.com/6FLEIZ6

 

 

Highlighted
Expert

Re: Modem Randomly Reboots


@alienist wrote:

Your Log shows Wifi interference.


Perhaps, but the poster stated that the device "reboots randomly". "WiFi interference" can not cause that to happen..



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!
Highlighted
Expert

Re: Modem Randomly Reboots

.@homeuser66

 

Perhaps it would be best for you to get a tech out to investigate. 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? Mark the post as Best Answer!
Highlighted
Most Valued Poster

Re: Modem Randomly Reboots

"WiFi interference" can not cause that to happen.." Why Not?

Highlighted
Frequent Visitor

Re: Modem Randomly Reboots

Had tech out. Levels are all fine. The broken port might have something to do with it, but he's not sure. The port issue will be fixed by a line tech.
Since I fixed the line in, I haven't seen any issues yet. But then again, it's still early. It's only been a few days. Usually happens a few times a month.
I've attached 2 screen shots of my levels from modem. The top one is my current levels , after I fixed the line at ground block. The 2nd one was from before.
Attach14496_20200517_090618.jpg
Attach14430_20200516_192605.jpg
Highlighted
Expert

Re: Modem Randomly Reboots


@alienist wrote:

"WiFi interference" can not cause that to happen.." Why Not?


You misunderstood me. I'm talking about that "WiFi interference" can't cause it to reboot spontaneously as they have stated in their topic title.



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!
Highlighted
Expert

Re: Modem Randomly Reboots


@Homeuser66 wrote:
Had tech out. Levels are all fine. 

The downstream power levels are still weak / marginal. There is a cable "tilt" problem at the higher frequencies.



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!
Highlighted
Frequent Visitor

Re: Modem Randomly Reboots

@EG

How do i fix that?
Highlighted
Expert

Re: Modem Randomly Reboots

I already gave you some self troubleshooting tips upthread. I also stated that if none of them apply then you need to book a tech visit. 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? Mark the post as Best Answer!
Highlighted
Frequent Visitor

Re: Modem Randomly Reboots

@EG<br>I already had a tech out (👆 my previous post as well). They didn't find anything wrong, except a broken port on the tap. I asked you cause I didn't know if they're was of I could personally do to fix it. Right now, it's beyond my capabilities since it's a home run directly from the ground block at some of house. No splitters no other equipment. Just a direct line to the modem. And the firings are from Comcast, not push on one's from home depot. There is no "s_uck out" either. Everything seems clean on my end.
Highlighted
Expert

Re: Modem Randomly Reboots

Well they didn't fix it properly. The numbers don't lie.... You'll need to get the techs re-involved or just live with it. The choice is yours...

 

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.




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!
Highlighted
Frequent Visitor

Re: Modem Randomly Reboots

Thanks! I'll keep on them
Highlighted
Frequent Visitor

Re: Modem Randomly Reboots

@EG

Update:

I had the tech out May 18th. The only thing Jr found (the I told him about) was a broken port on the tap. I since then, put a 15 DB amp on my line in my house. I never had the issue since. The other day, June 2nd, a line tech came out and changed the Tap. I still have my amp hooked up. I'm afraid to take it out cause it's been fine and my wife needs it to work from home. So I can't test it with it disconnected. This is a screen shot of my current levels.
20200604_091559.jpg
Highlighted
Expert

Re: Modem Randomly Reboots

Thanks for posting back ! It's a bit on the high side, but if it's working for you then let it ride. 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!
Highlighted
Frequent Visitor

Re: Modem Randomly Reboots

@EG
Thanks!
What numbers and channel are you looking at? I can tweak it or work on it more (like move modem closer to ground block).
Highlighted
Expert

Re: Modem Randomly Reboots

The upstream power is preferable to be between 40 and 45 dB.



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!
Highlighted
Frequent Visitor

Re: Modem Randomly Reboots

OK.. Thanks.. Not sure how to fix that.. I'll just let it be I guess.