C7000-100NAS randomly drops internet connection

[DarrenM]

Hello Rreckr 

When do you seem to have the most drop outs is it at a certain time of day?

DarrenM

[Rreckr]

DarrenM
There doesn't seem to be a time of day that the problem is worse. It will randomly drop out when accessing the NAS from the Blu-ray or using the wired desktop PC. Ive been calling Gear head tech support every morning for the last few days. This morning they decided that the problem is the modem. They required a copy of my sales receipt because there was a problem with the serial number. So I emailed what they needed in order to work on a replacing the modem. Hope to hear back from them within a day or two. But when I have issue again in the morning I plan on calling again to check.

[DarrenM]

Hello Rreckr

When you are having these issues can you copy the modems logs and post them here you can get the logs in the modems settings then click Advanced-Administration-Logs.

DarrenM

[polishkaz]

DarrenM, I am having very similar issues.  My ISP is Cox cable, currently my router is running Version V1.01.18.  The Netgear website states for this service provider I should only be running Version V1.01.15.  Whats up with that, who is right?  Is there anyway for me to download and install this older version?  Cox claims they can't push it and I can't find it in the download section of the Genie or website.  

[DarrenM]

Hello Polishkaz

It could just be old info on the web page but there is no way to change the firmware on cable modems whatever the ISP is pushing to the modem is what firmware it will use.

DarrenM

[dc2012]

So I have been having the same problems as everyone else. Started about a month after I got the modem. I just RMA'd the thing after living with it for 5 months. New one has the same problems. BTW, Netgear made me pay to ship their faulty product back to them. My current workaround is putting the Netgear router into bridged mode to act as a modem only, then using my old asus router to do all the routing. Works A LOT better. I don't know how much longer this will last, but I'll update if it starts going back to crap.  I think the Netgear router has a HUGE buffer in it to make up for lack of hardware. This is causing MAJOR ping Spikes.  I was having an average of 500 to 1000ms hops on a trace route before. Now I'm back to under 30 on most hops. I'm hoping this continues to work out, but if I wasn't going to be using a combo modem I would have stuck with my existing and slower setup. I'm on time warner. My lines and connections have been checked by a two pros (one who was an independent) and are good. The fact that my old docsis 2.0 modem runs faster right now says way too much. Disappointed, and Pissed at the wasted money. NETGEAR please replace this POS with something else, make a firmware that works, or give us a CHEAP upgrade path. 

[polishkaz]

DarrenM, I ended up having to buy another companies Modem and router and everything works perfectly.  Haven't had a drop out in weeks.  I am not sure what is up with this product but it is certainly not worth the money I paid for it and we should be refunded.  The thing worked in Bridge mode without dropouts but thats not what I bought it for.  Lesson learned, no more Netgear products.  

[reustin]

We have this router as well - wanted to add my complaint to the list and also ask some questions.  I'm a little surprised no one has included this info: what kinds of machines/operating systems do you guys have?

We have two MacBook Airs running El Capitan (10.11.6).  These are our main computers and they both drop the internet connection every 3-15 minutes.  It's MADDENING.  We have the 2.4 and the 5 GHz networks set up, so when it freezes, we just switch to the other one and it gets us another 3-15 minutes.  

But on our other devices the connection is fine and never drops out:

Toshiba PC running Win 7

2 iPhones running iOS 9.3

Apple TV 

...so it seems to just be the mac computers.

Do you guys that are having problems also experience them on Macs or only on Macs or on other types of devices?  

Thanks.

[NCsandhills]

The "wi-fi" connection depends on two pieces of hardware. The PC's adapter and the Modem/Router.

Since some of the connected units remain "connected" while the MacBooks tend to disconnect - you may need to check the adapter's hardware and settings.

Maybe the adapter's "energy or sleep setting" is allowing the adpater to turn-off when transmission is inactive??  Otherwise, check if the adapter's drivers are up to date, and if the settings are correct. The situation you are experiencing suggests that the problem is most likely the Mac PC's, and their adapter hardware and/or settings -- or possibly some other MacBook setting that causes the disconnect. 

[reustin]

Thanks for your reply!

Absolutely agreed–it must be something about the MacBooks' ethernet adapters or their firmware/drivers/software specifically.  However, neither of us experience this issue with any other WiFi access points, so it's also something about the combination of our computers AND this particular make & model of router (and we had no issues until we got this router recently). Neither Apple or Netgear is off the hook!

I was hoping to see if other people here were experiencing this correlation of it happening specifically with Macs as well.

PS: As to sleeping/inactivity; this happens while we are in the middle of streaming or browsing etc. 

P.P.S. I'm also an NC native (triangle area) 🙂

[8th_Day]

We us both Mac and Windows on our network.  They are wired and not wireless.  We have issues with both. 

Windows 10 Pro - Toshiba

Macintosh ElCapitan 10.11.6 - Imac 27in

This is getting so bad, that we almost couldn't use the internet yestserday at all.  Here is the log taken this morning at 9:30.

[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Fri Jan 27 09:00:48 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Fri Jan 27 09:08:34 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.76.76, port 53	Fri Jan 27 09:12:52 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 09:35:18 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 09:41:30 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 09:47:58 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.76.76, port 53	Thu Jan 26 10:01:31 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 10:10:58 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 10:15:15 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.76.76, port 53	Thu Jan 26 10:22:44 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.76.76, port 53	Thu Jan 26 10:38:43 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 10:52:31 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 11:10:30 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.76.76, port 53	Thu Jan 26 11:37:25 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.76.76, port 53	Thu Jan 26 11:45:00 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 11:50:11 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.76.76, port 53	Thu Jan 26 11:55:33 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 12:05:37 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 12:10:07 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 12:13:58 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 12:15:18 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 12:20:37 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 12:25:32 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 12:38:58 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 12:46:40 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.76.76, port 53	Thu Jan 26 12:48:57 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 12:54:22 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 12:58:07 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 13:08:37 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 13:16:09 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 13:35:50 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 13:54:54 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 14:09:41 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.76.76, port 53	Thu Jan 26 14:24:34 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 14:25:47 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 14:34:35 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 14:37:45 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.76.76, port 53	Thu Jan 26 14:38:32 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 14:45:13 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 15:20:04 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 16:38:44 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 17:13:46 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.76.76, port 53	Thu Jan 26 17:14:01 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 17:15:56 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 17:20:04 2017
[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53	Thu Jan 26 17:43:39 2017

[polishkaz]

Mac's, Iphones, Smart Tv's, Playstation 4's everything loses.  Going on a month now, not a single disruption to my internet with the new Modem and Router.  Do yourselves a favor, buy some new equipment and let me know when that class action lawsuit happens, I'll sign on board.  

[garybaird]

I don't know if I need to be notified when the class action happens. I am comfortable to know that I will never purchase another Netgear product EVER. I have save all of my many devices over the years for some dumb reason. But, I threw this Netgear device and all previous devices in the trash. I have replace this setup with ASUS and it works great. Since then, I have bought other equipment like wireless extenders. Even though Netgear claims to have good stuff in these areas, I did not buy theirs and NEVER EVER will again EVER>

[dc2012]

So I just had a third phone call with Netgear and this one was BY FAR the worst one. THe lady insisted on me going through all her stupid scripted crap, even though I had already been through it. Then she insists it takes 12 hours for the settings changes to work. 12 hours???? BS They are just trying to cycle the phones. Half an hour wait just to talk to her. CLUELESS. I told her about the traceroute pings and the connection dropping and I might as well have been talking french because she didn't know how to respond, so she went back to her script!

POOR SERVICE FOR A POOR PRODUCT.

They need to give me a working one or give me my $240 back.

[crazyrat]

Garybaird,

what is your recommended asus setup (models)?  Are you with Spectrum?

I fought with Netgear for the past 3 months with issues with my C6300 dropping wifi.  After swapping my modem twice, they decided to "upgrade" me to the c7000. Now I have THIS problem. I don't have the patience to go through another saga with their Gearhead (blockhead!) support even though I still have a few months left on my extorted "contract". 

Crazyrat - don't buy Netgear 

[8th_Day]

We have Comcast and UPnP is off on the NetGear Not sure why, but when we get a

[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53

75.75.75.75 is Comcast's DNS Server

Our connection is non usable.  We also have Magic Jack and when calls are coming in, we answer and loose incoming audio for about 5 to 15 seconds. 

When this happens, I check the logs and it shows this [DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53 in the logs. 

Comcast inside guy says that his meter shows Frequency 603 Errors, while the lineman says that is not what his meter shows.  We now have a monitoring device on our pole until Friday.

I am at a loss at this time.  Does port 53 have to be open to incomming traffic or can I shut it off some how on this modem.  I could do that on my zoom.

During the issues below, our use of the internet is dead.

2017-2-1, 04:53:26	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=b0:7f:b9:d7:20:80;CMTS-MAC=00:01:5c:7f:9a:5a;CM-QOS=1.1;CM-VER=3.0;
2017-2-1, 04:53:29	Warning (5)	MDD message timeout;CM-MAC=b0:7f:b9:d7:20:80;CMTS-MAC=00:01:5c:7f:9a:5a;CM-QOS=1.1;CM-VER=3.0;
2017-2-1, 04:53:30	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=b0:7f:b9:d7:20:80;CMTS-MAC=00:01:5c:7f:9a:5a;CM-QOS=1.1;CM-VER=3.0;
2017-2-1, 04:53:36	Warning (5)	MDD message timeout;CM-MAC=b0:7f:b9:d7:20:80;CMTS-MAC=00:01:5c:7f:9a:5a;CM-QOS=1.1;CM-VER=3.0;
2017-2-1, 04:53:37	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=b0:7f:b9:d7:20:80;CMTS-MAC=00:01:5c:7f:9a:5a;CM-QOS=1.1;CM-VER=3.0;
2017-2-1, 15:10:50	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=b0:7f:b9:d7:20:80;CMTS-MAC=00:01:5c:7f:9a:5a;CM-QOS=1.1;CM-VER=3.0;

All ideas and suggestions are welcome.  There is something causing all of this.

Do any senior techs actually monitor these posts?  If this kind of customer feed back happened in my business, I would be out of business.

Suggestions welcome.

[NCsandhills]

Try using OpenDNS for reliable access to the internet and protect against attack.  This is a free service ("Home" version of Cisco's OpenDNS).

You can review this option at "www.opendns.net".  The service directs internet connections to through safe links.  A simple change to either the computer's or router's domain server addresses.  It may help with stopping the DoS attacks (unless they are coming through IPv6).

Some anti-virus, etc., programs will shut-off internet service if the computer is under attack.  The external attack may also attempt to corrupt the router settings.  The OpenDNS domain settings (and service) are designed to prevent such incoming attacks.

NetGear's "parental settings" (via OpenDNS) allow the user to block access to selected internet sites (most which tend to cause DoS, and other nasties).

The OpenDNS service will not correct hardware issues that may related to NetGear's router malfunctions.

[NCsandhills]

Have you checked the "Port Scan and DoS Protection" settings on the router?

See: "http://kb.netgear.com/19957/What-does-Disable-Port-Scan-and-DoS-Protection-do?cid=wmt_netgear_organi...".

I had some problems and found a reference to "disable" this setting - and afterwards the problems ceased.

You can check your system's response with the setting enabled and disabled to see if that makes a difference.

Using OpenDNS to name the server domains will also help.  See: "www.OpenDNS.net" for details.

Do not disable any firewall or anti virus protection on your computer. 

[8th_Day]

Thanks for the response,but Disable Port Scan and DoS Protection is not checksed so it is supposed to be on and Respond to Ping on Internet Port is also unchecked, so it doesn't respond to a ping.

Just so you know, the url is opendns.com and opendns is now a part of Cisco.

The comcast line staff have been out and set up monitoring of my line.  I had two significant drops thus far.  They are now monitoring every box from our pole  back to the main switch.

I propose to them that I change my DNS location and see if that helps.  They thought it a good idea.  Don't understand why the Comcast DNS server would DoS Attack my IP.  

Is anyone else on Comcast having the same issue in the Chicago area for 75.75.75.75  or 75.75.76.76?

[jacooper01]

I think I may have found a solution...at least for me. 

I purchased one of these C7000-100NAS  units and swapped it back for another one. I too had Comcast say that they could find NOTHING wrong. 

I put the router into bridge mode, and called Comcast one last time. They wanted me to put the unit back into router mode; in an effort to be expeditious, I performed a hardware reset to get it back into router mode.  

Note that this reset is not just a disconnect from power and restart, it is a full hardware reset where the reset button is pressed and held for 7 seconds ( I held for 20). 

That did the trick! 

I did not see anyone in this thread mention a hardware reset as described above.  Many think a disconnect from power is a reset.I have reset it three times and it works like a champ.  No delay...performance is fantastic. Been running for a couple of weeks!

This may not resolve everyone else's issue but it sure resolved it for me. 

When this unit works, it screams. 

Good luck to everyone. 

[BigDog2017]

C7000 started dropping connection yesterday. Comcast does not appear to be the issue. Logs on the router make it hard to pinpoint what really is going on. I am suspecting the router and if that is the case I will set the thing on fire and never buy another NG prodiuct. The event logs do have some really odd date stamps. 

Time	Priority	Description
2016-12-15, 01:58:51	Critical (3)	TFTP Request Retries exceeded, CM unable to register
2016-12-15, 01:58:54	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.0;CM-VER=3.0;
2016-12-15, 02:00:28	Critical (3)	TFTP failed - Request sent - No Response;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.0;CM-VER=3.0;
2016-12-15, 02:00:28	Critical (3)	TFTP Request Retries exceeded, CM unable to register
2016-12-15, 02:00:33	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.0;CM-VER=3.0;
2016-12-15, 02:01:29	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.0;CM-VER=3.0;
2016-12-15, 02:01:32	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.0;CM-VER=3.0;
2016-12-15, 02:01:51	Critical (3)	No UCDs Received - Timeout;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2016-12-15, 02:01:55	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2016-12-15, 02:04:29	Critical (3)	TFTP failed - Request sent - No Response;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.0;CM-VER=3.0;
2016-12-15, 02:04:29	Critical (3)	TFTP Request Retries exceeded, CM unable to register
2016-12-15, 02:04:34	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.0;CM-VER=3.0;
2016-12-15, 02:04:57	Critical (3)	No UCDs Received - Timeout;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2016-12-15, 02:05:01	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2017-1-8, 12:33:56	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.1;CM-VER=3.0;
2017-1-8, 12:34:32	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.1;CM-VER=3.0;
2017-1-14, 18:19:38	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.1;CM-VER=3.0;
1970-1-1, 00:00:37	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:00:44	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.0;CM-VER=3.0;
2017-1-29, 15:34:59	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.1;CM-VER=3.0;
1970-1-1, 00:00:37	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:00:41	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:01:11	Critical (3)	No UCDs Received - Timeout;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2017-3-11, 13:59:04	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.1;CM-VER=3.0;
2017-3-11, 13:59:10	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.1;CM-VER=3.0;
2017-3-11, 13:59:11	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.1;CM-VER=3.0;
1970-1-1, 00:00:37	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:00:41	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:02:55	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:02:57	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2017-3-11, 14:14:40	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.1;CM-VER=3.0;
1970-1-1, 00:00:37	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:00:42	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:00:37	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2017-3-28, 17:00:30	Critical (3)	Resetting the cable modem due to docsDevResetNow
1970-1-1, 00:00:38	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:00:40	Notice (6)	WiFi Interface [wl0] set to Channel 8 (Side-Band Channel:N/A) - Reason:INIT
1970-1-1, 00:00:40	Notice (6)	WiFi Interface [wl1] set to Channel 149 (Side-Band Channel:N/A) - Reason:INIT
1970-1-1, 00:00:45	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=a0:04:60:f5:19:a8;CMTS-MAC=00:24:c4:27:b9:39;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:00:51	Notice (6)	Honoring MDD; IP provisioning mode = IPv6

[NCsandhills]

As mentioned in an earlier post - try a "hard reset" to re-establish the default settings and possibly correct some hidden fault that is affecting the operation.

The "hard reset" will also re-establish the MAC addresses for the Cable Modem (default on the nameplate), plus the MAC addresses for the LAN port and the INTERNET port.  The later are sequental (in last 2 numbers) to the default Cable Modem MAC address.  After the hard-reset, change the "default" login username and password for the Cable Modem (for security), and reset the Internet password(s) to those previoulsy used - this should allow all previously "attached devices" to connect.  Leave all other settings alone until you can determine if the problem is corrected.

[BigDog2017]

That isnt a fix. its a bandaide. root cause needs to be determined and addressed.

[NCsandhills]

Depends on how long the Bandaide lasts. Possibly the ISP is changing a setting not available for endusers to access and a "hard reset" is the only approach.

Another question for "lost internet service" - folks should determine (if possible) if the wreless connection between the PC and Modem/Router is failing, or if the ISP feed to the Modem is failing. If a hard drive (for example) is attached to the LAN port of the Modem/Router, and the PC can read and download a file from that drive, yet unable to reach the internet - then that would indicate an problem with the ISP feed or Modem's operation.  If the PC can not reach a LAN connected device, then that might indicate an issue with the PC's WiFi adapter or the Router's operation.

Regarding the PC's WiFi adapter - items to check are: set to max power at all times, and not allowing the PC to turn off the adapter to "save energy". These settings are OK for desktops, but might drain the battery on laptops.

It is difficult to troubleshoot a "combined" modem/router device, since the issues are difficult to separate - i.e., is it the ISP's signal, the modem, the router, the PC's adapter, etc.  Installing a LAN device can help to separate some of the issues, but not all.

[BigDog2017]

I can appreciate your reply and I do agree a process of elimination needs to happen in order to determine the root. My snarky comment about a reset being a bandaide is simply that a hard reset does not change the hardware or the firmware of the router. Yes, it can reset data parameters and it can solve sync issues, but it does not solve the bits that created the problem in the first place. Doing a reset is not a perm fix. Be asured, proper network troubleshooting has been done. When all 20 devices (hardwired and wireless) drop internet at the same time, I am very confident it is a router issue. It is not a LAN issue. All devices have their permitted LAN functionality even when the internet drops. Even checked the 4 swtiches on the network just to be sure. So, this leaves the problem at the router or comcast, or both. Given that prior to the C7000 being on our network, it was very reliable, it is very suspect.