Is it Spectrum is it the wiring or is it the modem?

[Twistfaria]

I've had issues with my Time Warner that's now Spectrum service for several months now. Back when we leased their piece of crap modems, service was always spotty so we bought our own Netgear Nighthawk modem router combo in Oct 2015. From what I remember it was decent for awhile but then it would start to drop the connection or just be really slow. Paying for upgrades in speed improved the slowness issue. For several months I have used their chat support and had them do their little "send fresh codes" song and dance thing and the connection issue would get better for awhile until I had to do it again in a few weeks. Fast forward through months of doing that and it has gotten much worse now.
It's the weirdest thing, I've had to troubleshoot our routers and modems for the last decade or two and I've never come across one that does this. What will happen is it will say that it is connected to the internet, it will show all the bonded channels and everything in the modem software, it will appear to be updating the connection every so often even, but I will not be able to open anything. Most of the time it can be repaired by going into ipconfig in command prompt and releasing and renewing, or doing the same thing within the modem software. For some reason this works better than just doing a modem reboot. However at this point it will only fix it for a limited amount of time ranging from a few minutes to several hours.

Finally we decided that we needed to have them out to check the wiring which they did and said that the pole to house wire showed a lot of static and they replaced it. He couldn't get to the wire at the modem end to test because it is behind furniture and in an inaccessible area right now but he did look in the attic and said it looked fine and there were no bites, splits or bad connectors to be seen. I was really hoping that the wire would be the issue but apparently it wasn't or at least wasn't the only issue. I'm still dropping the connection to the isp. At this point I'm not sure if the issue is with the wire in the attic, the wire from the wall to the modem or the modem itself!! Any help insight into these symptoms would be greatly appreciated.

Some information on my setup:
Netgear C7000 – Nighthawk AC1900 modem/router
My desktop is hardwired directly to it.
It is broadcasting both a 2.5GHz and a 5GHz SSID and we have a TP link power line adapter with the same setup to extend the wifi coverage to the downstairs better.
We have a 300Mbps connection with around 15 different devices hooked in, iPhones, TVs, satellite, iPads and computers.

While writing this I started to wonder exactly how the power line adapter set itself up so I paused and went into its software. Sadly I then realized that I had never actually done anything in its software and had relied on its easy setup to do the job. -_- I'm not entirely sure how it does its connections but I did notice that it had a dynamic ip address that was inside the DHCP range of the modem it's hooked up to. Not sure I needed to but I went ahead and changed it to a static ip outside the range. I've spent so many hours reading so many different things online about networking over the years my brain has started to turn to mush on this subject. Again ANY advice or recommendations, heck even commiserations, would be appreciated!!!

 

[SgtScream]

First of all, your ISP stated the found an issue and that they "FIXED IT". I'd call them back up and tell them the issue is still there and that they didn't fix anything.
The best thing you can do is hardwire your desktop/laptop directly into the modem. If the issue persists, then its on the ISP to fix the problem, because it's their connection and its their modem.
If the issue does not replicate after doing this, then the issue is either with the router or the wiring in the house.
That's the first step. Finding out on which side of the demarcation point where the issue resides.

 

[Twistfaria]

As I said in my post the modem is mine not theirs! I also already said that my pc is hard wired to the modem, always! The issue is present on both wired and wireless connections. The only way I could know that it is the modem definitively is to buy a new modem which I really didn't want to do unless I had to, as the one I have is not even two years old and cost upwards of 300$! I've already checked the Netgear warranty and it expired last year!

I came here hoping that someone could recognize these symptoms as originating from a certain source and could advice me what that source is.

As I said they can not access the wire at the modem end, to test it, as it is behind large heavy furniture in a room that has no room in it for that furniture to be moved out of the way!! If it is indeed a malfunction of the wire in the difficult to navigate attic then they would have to come out and run a new wire to a new location in a different room!

In my brain my next move is to replace the things that I have access to, meaning the coaxial cable from the wall to the modem and then the modem itself. However I wanted some other opinions and suggestions before making those purchases. The coaxial has to be a right angled one because of how close the furniture is to the wall. It will be difficult for me to access the wall outlet to change out the cord but I'm hoping that I can manage with a long grabbing tool.

Not to be overly salty but if you are going to leave "help" please at least read the question fully.

 

[boosted1g]

This one of the reasons why a seperate modem and router are ideal instead of a combo device.

So you cant wire it direct to modem, you can only wire it to your router, and thus they can just find 1 of a 100 reasons to blame the router.
If you had a dedicated modem only then it is much harder for them to argue.

Go into your modem logs and look for anything saying T3 or T4 timeout errors. This indicates that the modem is having difficulty maintaining a connection to the ISP. If so then you can ask a service technician to come out again, and also to bring a standalone model for testing purposes, if that modem also gets errors then it has to be the connection.
Also what is the DB power level of your bonded channels, ideal you want -7 to +7 of power, anything else is a problem. If low they need to look on their end, if high then you may need an atenuator

Now with all of that said, 90 degree adapters are notorious for having bad connections.
What you may need to do is get a barrel plug adapter (the male to male plugs), connect it to cable in wall, and then get a mesh or recessed pass-thru wallplate that will allow a cable to come back out.
This is a recessed wall plate:

 

[boosted1g]

FYI sometimes you have to be very deligiant with TWC/Spectrum. I was plagued with having inconsitant disconnects and decreased speed, of course when the tech came out it was always good because it was before people where home from work and thus traffic demand in the neighborhood was low.

After many tech calls they had an engineer keep logs on my specific connection to ultimately find out there was a bad coax crimp on their end. In my neighborhood they have the box where the fiber comes in and then they branch out the coax to a another smaller hub with 4-6 houses on it. It just so happened that I was the only active internet customer on that smaller hub at that time so there was no one else having the same problem to think the problem was on that side of the connection.

 

[Twistfaria]

Thanks for the reply. OK so all 24 downstream bonded channels are within the range you said. If you are talking about the ones labeled dBmV it looks like they are all between -3.7 to -1.6. There are two different sets of logs but I'm going to assume you meant the one that says "event log" and there does seem to be a number of the T3 time outs. Sadly I can't tell when the majority of them happened as for some reason several of them say they happened the 1st of January 1970!! O__O Not sure how or when it lost its time or why it would have chosen the 70s!

Here is the weird thing though, I haven't had a single issue since I asked this question which is when I changed the tplinks ip address. Is it possible that changing that or rebooting the tplink could have anything to do with it suddenly seeming fixed? To my eternal shame I don't think I had ever rebooted the tp link since I installed it a few months back. The only other thing that has changed since then is that one member of the household is away so there are less devices on the network. I've been monitoring the situation holding my breath waiting for the other shoe to drop and will continue to for the foreseeable future.

Also I know I've read somewhere that routers have a hard time fully rebooting if there are still devices connected but I have no idea if that is actually valid information and I find it next to impossible to disconnect all the various tvs, pcs, ipads, phones......what have you before a reboot. Is that info accurate? Should I be making sure that everyone and everything disconnects first?

I totally agree with you on TWC/Spectrum and what you described sounds like a nightmare!! Every time I had to do chat support with them I always ended up irritated at their lack of knowledge and the repeated guaranties that this would never happen again. One time I even had someone say that they had gone into my router and changed the channels to the "recommended" settings. When I responded asking how exactly they had gotten into my password protected personal router, with all remote control turned off, they evaded the question and on repeated questioning eventually said "oh no I was confused that was a different customer". Seriously? How many people could they possibly be chatting with at the same time?!! Another time I had someone mention "clearing flaps" which I had never heard before so I looked up what that was. After finding out that flaps measure the number of times your connection gets dropped and that high flap numbers mean connectivity issues I asked him what the flap numbers were. He responded by saying that "oh flaps aren't numbers they are just something that help a connection when cleared".

I had my own suspicions about 90 degree adapters and will most likely try to change that sometime in the future. Thanks so much for the help!!

 

[boosted1g]

2 dbm difference among the channels is good, if you started seeing 5 or more that could cause issues.

The date thing is completely normal, you have to look at the log after it to get an idea on time.

It is possible that you have an IP conflict (which can cause a lot of issues on a router) between tplink powerline and another device. This is assuming one device had a static IP and the other had a dynamic one that was the same.

Routers dont have a problem rebooting. Now they can have a hard time getting devices to reconnect. When allowing the DHCP server on the router to assign IP addresses it gives them a lease time for that address. So lets say computer A has an IP ending in .101 and computer B was off or has an expired lease. If computer B asks the router for an address first before A, then the router could assign .101 to B even though A thinks it is still using .101.
Hope that makes sense.
The best solution to this issue is to use static IPs. You can manually set a static IP at the devices but for mobile devices like laptops and phones this is quite annoying. The easier option on most higher end routers is setting up a custom static routing table where you can tell your router to always assign the same IP to the same device; this way you get the pros of static IPs without the cons of having to change settings on device anytime you connect to a different network.

 

[Twistfaria]

Yeah the main reason I wanted to check the TP link device was because I wasn't certain how it worked. I used to have another router, to extend coverage, that I had to make sure wasn't acting as a second DHCP server so I wouldn't have those IP conflicts. There was no mention of DHCP in the tp links software so I assumed it doesn't act as one. I'll have to look into trying to set up a static routing table. I can never figure out why several of the connected devices never display a name, in the router software, while others always do. Makes it hard to monitor who's on my network! Not that I'm afraid of piggybackers since I live out in the sticks and my wifi is always password protected anyway, I just like to play it safe.

 

[boosted1g]

Basic powerline adapters do not have an IP address, they are transparent to routers/switches. To the network, they are what is categorized by the OSI model as a layer 1 device, the router just thinks it is connected direct to device with ethernet.

Now some of them have switches in them with some logic so those could have an IP address and the ones that also have a built in acess point will have an IP address.

So here is how I have DHCP setup in my house.
DHCP (for temp devices) is from .80-.99, then my static leases are from .115-.160. I have things tiered so IP cameras are in the .150s, PCs are .120s, home theater/media equipment is .130s, phones/tablets 140s etc.
I allow friends/family on my primary network which is why I have a 20 device DHCP pool.
I do have a seperate VLAN setup (guest network) for when I need to connect infected devices or if I am doing something advanced for family/friends so I can match it to what their home network subnet is.

Now most routers will be that way where your router's static leases are OUTSIDE the DHCP addresses, but on some it has to be INSIDE the DHCP pool. This is for static leases set in router firmware, when static IP set at the device then he address always needs to be outside the DHCP pool.

 

[Twistfaria]

This issue came back after being dormant for about a week. I found a LONG thread about people having really bad connectivity issues with the Netgear Nighthawk c7000-nas100 that went back about 18 months. I have no idea how I missed this while researching over the last several months! So I decided that it was the modem/router causing this issue. I have now purchased and setup a TP-Link DOCSIS 3.0 (24x8) Modem and a TP-Link AC1900 Archer C9 router. I figured I might as well separate into two devices for any future troubleshooting issues.

I managed to set everything up and had to do chat with spectrum since their "modem activation" portal didn't work AT ALL. I'm a little leery of the new router software as it looks VERY different to the Netgear stuff I've been working with for many years. It has a lot of new information and possible settings that I'm totally unfamiliar with and a few things that I'm just not finding such as a scan of the nearby wifi channels. It also came with IPv6 defaulted to off and when I turned it on it doesn't appear to be working. I've set it to Dynamic IP SLAAC/DHCPV6 and tried to release and renew but the "IPv6 Address" is blank. It I go into my hardwired PCs local area connection status it says no internet access for IPv6 connectivity. I tried giving it the google IPv6 DNS addresses. Not sure what I'm doing wrong here but I could use some more advice.

I know that my ISP supports IPv6 because I had it on the Netgear. The new modem also supports dual stack.

Side note: My iPhone is having issues staying connected to the new router even when it's 5 feet away! I'm wondering if the same setup I had before with the powerline adapter cloning the wifi isn't working anymore. I want it to be a seamless transition to the strongest signal as I move around my house so I set it up to be the same SSID and security protocol. The only setting that is different is that before I had them set to a static channel rather than set to "auto" which it is now. Should I set them to be a static channel? If so should it be the same channel or different ones? I read different info every time I look!