C6250 Internet Dropping With Strong Signals

[ChopShoey]

C6250-100NAS

Firmware Version: V1.01.26

Provider: Cox Communications

Our internet drops most days a few times while we are attempting to use it. When it occurs, several devices will lose connectivity even when they were previously utilizing the internet. We think that when a device is connecting there is a greater chance for the internet to drop (often with my wife's windows 10 tablet as it frequently sleeps, and the internet drops when she connects).

I can fix the problem by logging into the administration page, clicking on advanced -> connection status, and doing a release/renew cycle. I do NOT have to restart the router or disconnect my devices and the internet will come back on for all of my devices.

We have approximately 10 devices connected at a time, split pretty evenly between 2.4G and 5G.

I called my ISP and they did some diagnostics. They indicated that the signal to my device was strong and suggested that NetGear support may be required. My 90 day service has expired for the modem/router.

I find that there are many instances of DoS attacks on the logs, such as: 

[DoS attack: TCP- or UDP-based Port Scan] from 68.105.28.11, port 53

[DoS attack: TCP- or UDP-based Port Scan] from 68.105.28.12, port 53

I'm not sure what other information to provide at this point, I'd appreciate any insight.

[plemans · Accepted solution]

You have massive amount of errors in your line. 

Here's where I'd start.

Move the C6250 to where to coax enters the home. Remove any splitters, amplifiers, attenuators from the line. Preferably just direct connect it. Then see how it works. Use it for a bit and re-do the modem connections page.  If you're errors are gone, its something within the wiring if your house. If they aren't, your ISP needs to check your line running to the house as you have issue with the line. 

Your strength is within limits but even that is variable. There should only be roughly 3.5dbmv between channels and you're running from 3.1-8.9dbmv. 

so there's some issues with your line. 

[plemans]

Cox is very good at blaming 3rd party equipment and saying a signal is fine (even if it isn't). All they're checking for is if they can signal it. 

Log into the C6250 and look at the modem connections page. Take a screen snip of this. make sure to get all the details. It shows us signal strength and line issues. Keep in mind that its a snap shot in time. 

another question. Do all device drop or only wifi devices? Just curious if its a wifi issue or a connection back to the isp .

[ChopShoey]

@plemans , I've attached the current connection information.

I'm not sure if wired connections get the same drop, we don't use them as much. We know we've seen the wired connection drop before, but I'm not sure if it drops at the same time as everything else. I can certainly test next time we see it.

[plemans · Accepted solution]

You have massive amount of errors in your line. 

Here's where I'd start.

Move the C6250 to where to coax enters the home. Remove any splitters, amplifiers, attenuators from the line. Preferably just direct connect it. Then see how it works. Use it for a bit and re-do the modem connections page.  If you're errors are gone, its something within the wiring if your house. If they aren't, your ISP needs to check your line running to the house as you have issue with the line. 

Your strength is within limits but even that is variable. There should only be roughly 3.5dbmv between channels and you're running from 3.1-8.9dbmv. 

so there's some issues with your line. 

[ChopShoey]

@plemans I lucked out on triggering the drop (my wife's tablet again).

Also, I wanted to mention that most devices seem to have strong wifi signal even when the internet is unavailable, so I'm not sure that it is related to the wired/wireless medium in use. 

[plemans]

You still have to many errors and your power still isn't within the range it should be between channels. 

[ChopShoey]

@plemans , I need to apologize. I missed the other message you sent and hadn't gone directly to the line yet.

Our setup was being split outside of our home, so I didn't go straight to where it comes into the home. I did remove the splitter and tap that were in the box so that the line would only go to the room where my modem is at. 

I haven't been resetting my modem, so the "correctables" and "uncorrectables" were just accumulating. Here is the data right after I got everything back up after removing my splitters. We don't actually use TV so they won't be necessary anyway.

It looks like between the channels individually they are in the range you specified now, if I'm reading it right... but I can't be sure.

[plemans]

A little high but still within spec. Try it and see how it runs

[ChopShoey]

@plemans Here is information after 20 minutes. Started streaming to put some data on the network.

Are the correctables/uncorrectables still high? It seems like it might be high still but I don't know what to expect.

Thanks for the kudos 🙂

[plemans]

Yes, you've still got quite a bit of errors. Probably worth it to have the isp check your line.
You're welcome for the kudos. Shows appreciation 😉

[ChopShoey]

@plemans after I forced the tech support to send someone out without charging me, they came out. Tech says "I don't even need to check anything, that little cable that you've probably been driving over is a bypass for the main that is out under your street." So it does seem that their service was the cause of the errors. I'll have to wait until they tear up the street and replace the main before I can do any more troubleshooting.

Thank you again for the help.

[plemans]

That'd definitely cause some issues! 

Sorry that you'll have the issue until they come run a new line but at least you know your equipment isn't at fault or your home. 

Sad that it took "forcing" them to come out. Kind of goes to show how helpful ISP's are at keeping their lines/equipment running in good condition.