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Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

I purchased the CM1200 modem back in March of this year and haven't had an issue with until the past month and a half. I'm having an issue where my internet will randomly disconnect on both Wired and Wireless at the same time. These disconnects can range from a couple seconds to a couple minutes. I called our ISP (Comcast) asking if they could find anything wrong and they told me that they were having no issues. I replaced our router, thinking that was the issue at first since the internet symbol on the modem stays on even during these moments of disconnect but the routers didn't. But the new router (TP-Link Archer C5400X) hasn't fixed it.

 

The modem is on the latest firmware version (V1.02.02). I've tried different ethernet cables on both the router and modem. On my router, I've tried changing channels, cloning my computers MAC address, setting up some IP configuration. On the modem, I enabled ethernet port aggregation. Nothing has worked so far. I'm thinking it's either a coaxial cable issue (but wouldn't my ISP see that?), or simply the modem itself.

 

Thanks for any help you can provide!

Model: CM1200|Nighthawk Multi-Gig Speed Cable Modem
Message 1 of 19
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Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

log into the modem and get a screen snip of the cable connection page and the logs and post them back here. 

Also, if you have any splitters, attenuators, or amplifiers in line, remove them and direct connect the modem. 

CM2000-> Arris W31-> GS716v2-> TP-Link M9Plus
Message 2 of 19
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Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

@plemans 

I'm not sure how to attach multiple things so I hope an Imgur link of the screenshots is ok: CM1200 Screenshots

Here is at least the event log if you're not ok with that.

Thanks!

 

Time Priority Description
Fri Jun 19 10:00:22 2020 Warning (5) Dynamic Range Window violation
Fri Jun 19 10:00:22 2020 Warning (5) RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 10:00:22 2020 Warning (5) Dynamic Range Window violation
Fri Jun 19 10:00:22 2020 Warning (5) RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 10:00:22 2020 Warning (5) Dynamic Range Window violation
Fri Jun 19 10:00:22 2020 Warning (5) RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 10:00:22 2020 Warning (5) Dynamic Range Window violation
Fri Jun 19 10:00:22 2020 Warning (5) RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:54:56 2020 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:54:30 2020 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:36:52 2020 Notice (6) CM-STATUS message sent. Event Type Code: 8; Chan ID: 79 80; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:36:26 2020 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:36:26 2020 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:36:26 2020 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:35:39 2020 Warning (5) Dynamic Range Window violation
Fri Jun 19 09:35:39 2020 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:35:38 2020 Warning (5) Dynamic Range Window violation
Fri Jun 19 09:35:38 2020 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:35:37 2020 Warning (5) Dynamic Range Window violation
Fri Jun 19 09:35:37 2020 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:35:37 2020 Warning (5) Dynamic Range Window violation
Fri Jun 19 09:35:37 2020 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:35:37 2020 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:34:54 2020 Warning (5) Dynamic Range Window violation
Fri Jun 19 09:34:54 2020 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:34:54 2020 Warning (5) Dynamic Range Window violation
Fri Jun 19 09:34:54 2020 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:34:54 2020 Warning (5) Dynamic Range Window violation
Fri Jun 19 09:34:54 2020 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:34:54 2020 Warning (5) Dynamic Range Window violation
Fri Jun 19 09:34:54 2020 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:34:54 2020 Warning (5) Dynamic Range Window violation
Fri Jun 19 09:34:54 2020 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:34:36 2020 Warning (5) Dynamic Range Window violation
Fri Jun 19 09:34:36 2020 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:34:36 2020 Warning (5) Dynamic Range Window violation
Fri Jun 19 09:34:36 2020 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:34:36 2020 Warning (5) Dynamic Range Window violation
Fri Jun 19 09:34:36 2020 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=28:80:88:b3:1f:d0;CMTS-MAC=00:01:5c:79:10:69;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 19 09:34:35 2020 Warning (5) Dynamic Range Window violation

 

Message 3 of 19
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Guru

Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

You have t3 errors and power fluctuation errors. The snip just shows in the time the page was loaded but from looking at your log, the power must be spiking/dropping. 

If you didn't check your line and remove amplifiers, splitters, attenuators, do it now. If you already have, then I'd have your isp check your line. 

CM2000-> Arris W31-> GS716v2-> TP-Link M9Plus
Message 4 of 19
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Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

I don't have any extra stuff like that added on. Looks like another call to my ISP! Hopefully that gets it resolved. Thanks for the advice!

Message 5 of 19
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Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

***Edit, wrong response. working on several at once. 

CM2000-> Arris W31-> GS716v2-> TP-Link M9Plus
Message 6 of 19
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Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

Any progress on this?


@KiwiBoxer wrote:

I don't have any extra stuff like that added on. Looks like another call to my ISP! Hopefully that gets it resolved. Thanks for the advice!


 


My Setup (Cable 900Mbps/50Mbps)>CAX80>RBK853 v3.1.16.6(Router Mode)
Additional NG HW: C7800/CM1100/CM1200/CM2000, Orbi CBK40, RBK50, R7800, R7960P,
EX7500/EX7700, XR450 and WNHDE111
Message 7 of 19
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Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

After a couple calls I finally got Comcast to send a tech. They'll be coming early tomorrow. I'll update again a bit after to see if it's fixed.

Message 8 of 19
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Guru

Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

Smiley Wink


My Setup (Cable 900Mbps/50Mbps)>CAX80>RBK853 v3.1.16.6(Router Mode)
Additional NG HW: C7800/CM1100/CM1200/CM2000, Orbi CBK40, RBK50, R7800, R7960P,
EX7500/EX7700, XR450 and WNHDE111
Message 9 of 19
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Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

So, the tech came and replaced the lines saying that they were super old and needed to be replaced. He said the levels are now even.

BUT unfortunately that STILL didn't fix the random internet disconnections. I tried to factory reset the modem to see if that would help but now the internet isn't working and I can't access the internet or the network IP site (I'm on my phones data right now). And yes I am directly connected to the modem. Downstream light is now blinking green and I know that means that it's looking for a downstream channel. Before I factory reset it I saw in the event logs that it was still getting T3 timeout errors but the one error about the 6 db is gone.

Another thing to note, for some reason the ethernet ports on the modem just wouldn't work when hooked up to anything that wasn't to the router. I would have to connect to the router to access the internet.

Definitely not having a fun time right now haha.
Model: CM1200|Nighthawk Multi-Gig Speed Cable Modem
Message 10 of 19
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Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

After leaving both my modem and router turned off for 20 minutes, the internet only works through being directly connect to my laptop. Nothing else works. Router doesn't get internet and neither does anything else directly connected to the modem or router. Also the downstream symbol stopped flashing.

Message 11 of 19
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Guru

Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

Possible the modem maybe bad. I would get another cable modem, maybe one from the ISP temporarily to see if a different modem does the same thing, if not, then return or replace the modem. 


My Setup (Cable 900Mbps/50Mbps)>CAX80>RBK853 v3.1.16.6(Router Mode)
Additional NG HW: C7800/CM1100/CM1200/CM2000, Orbi CBK40, RBK50, R7800, R7960P,
EX7500/EX7700, XR450 and WNHDE111
Message 12 of 19
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Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

I called Comcast and their reset signal seems to have gotten the internet back up but I doubt that'll hold. I'll start working on getting a a new modem to test. I'll update if either the disconnects seems to have stopped after the reset signal or I get the new modem and that works.

Message 13 of 19
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Guru

Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

Smiley Wink


My Setup (Cable 900Mbps/50Mbps)>CAX80>RBK853 v3.1.16.6(Router Mode)
Additional NG HW: C7800/CM1100/CM1200/CM2000, Orbi CBK40, RBK50, R7800, R7960P,
EX7500/EX7700, XR450 and WNHDE111
Message 14 of 19
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Guru

Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

I would have the isp check the line. 

When you load the cable connection page, it just shows the values at tthe time it was loaded. But your logs show range violations, power exceeds notices, and t3 errors. Its usually a sign that power is spiking/dropping and causing issues. 

CM2000-> Arris W31-> GS716v2-> TP-Link M9Plus
Message 15 of 19
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Guide

Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

I just got confirmation of a modem being sent to me. I'm going to wait for that to see if it resolves the issue. My ISP just replaced the lines anyways and said they should be good now.
Message 16 of 19
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Guru

Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

Let us know how it goes

CM2000-> Arris W31-> GS716v2-> TP-Link M9Plus
Message 17 of 19
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Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

Update: 

The modem replacement came in Wednesday night and hadn't fixed the problem at the time. But the event log wasn't showing any errors like before and the db levels were fine. Now, we had just replaced the router as well thinking that was the original problem, but it is a TP-Link router. Fortunately, I purchased a NETGEAR router cause the other router replacement was taking a while to be delivered. So I hooked that one up yesterday afternoon and everything since then has been working fine. Now I'm wondering why that is? The TP-Link router was a brand new replacement. Is it just not as "compatible" with the modem since it's not the same manufacturer? Also, I'm thinking that this whole entire thing was just multiple things that needed to be fixed. With my lines being really old and replaced (fixing the 6db error but still having the T3 timeout error), my modem being replaced and not showing anymore errors (but still randomly disconnecting), then using a router from the same manufacturer.

 

But once again everything seems to be running great. Thanks for assistance all. I'm a lot more knowledgeable about this than I was before.

Message 18 of 19
Guru

Re: Random Internet Disconnection on Both Wi-fi and Wired (CM1200 Modem)

It might have been a combination of things. There shouldn't have be any issues with mixing manufacturer's. I've ran many different models on my network between manufacturer's and never had issues. but maybe it was a 1 off thing. 

Glad to hear you got it working decent though!

CM2000-> Arris W31-> GS716v2-> TP-Link M9Plus
Message 19 of 19
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