WTF is going on with my router?

Factual Questions
1

Several months ago, I started having a rather enraging problem with my internet. It was going down, and then coming right back up. Then, a few minutes later, it would go down again, and come right back up. Over and over again, at random intervals of minutes or hours. As you can imagine, this made online gaming next to impossible, and trying to watch streaming video extremely frustrating.

After a few days of this, and discovering that the usual solution of unplugging the modem and router and then plugging them back in had no effect on the situation, I called Charter’s tech support. From what the tech guy could tell me, there was no evidence of any interruptions of service to my area (more on this later). He did observe, however, that I was using an outdated cable modem, and suggested I visit the local Charter office to exchange it for a new and improved one. So I got the new modem, hooked it up and got it activated. Alas, the problem continued. So maybe the problem was my Cisco router, which was just as old as the previous modem. So I hied myself to Office Depot and bought a brand new Linksys router, this one a dual-band job with the new 5G WiFi.
The problem continued. During another call to tech support, the tech guy suggested possible interference from other nearby routers. This wasn’t unreasonable - I live in an apartment building and a number of my neighbors have their own WiFi. My building is also in the downtown area, so I’m more or less surrounded by businesses with still more WiFi connections. In any case, for whatever reason, the problem completely stopped the next day, and I never had this problem again …
… until it started up again about two weeks ago.
Another call to tech support again confirmed that they could see no evidence of any service interruptions. As I mentioned, here is the “more on this later”. I described the problem as appearing to be the signal to the modem dropping - or being interrupted - for just a brief instant. Just long enough for the router to think it has lost the connection and forcing it to go through the whole handshake sequence to reestablish the connection. I had already described my home network to tech support: Everything, our TV, cell phones, and my wife’s laptop connect via WiFi; my personal computer, however, is using a wired ethernet connection to the router. This is because of my online gaming. Before I got married, my computer just used the WiFi. I didn’t own a TV, and my phone was a flip-phone, so my computer was the only device using the WiFi. After getting married, I discovered that, when my wife was watching Netflix on the TV, my latency while gaming shot up so high as to make my game unplayable. (My latency in WoW was typically around 50ms; if my wife fired up Netflix, my latency would shoot up to 800+ms, and sometimes into the thousands of ms.) I specifically noticed that the problem was not just affecting WiFi - it was also affecting my ethernet connection at the same time, so it didn’t seem to be a WiFi issue.
Tech support’s suggestion was to disconnect the router from the modem, and plug my ethernet cable directly into the modem. This was to test to see if the problem continued. So I followed her suggestion, and for 30 glorious minutes I gamed with no interruptions. Then I returned all the connections back to the previous setup, and the problem immediately returned, signal dropping and returning every few minutes. This pretty much confirmed that the problem was somehow related to my router, and Charter can’t really help me with that.

I have also more or less ruled out interference from the swarm of nearby WiFi. The problem has once again tapered off, and for the last few days I’ve had very little trouble with this … during the day. The problem is still occurring, but now mostly very early in the morning when I get up for work - I’m talking 3-4:00AM, hours before nearby businesses are open, and virtually all of my neighbors are asleep. Then it’s fine during the day, and then pops up again after 10:00PM. That’s when it started up tonight, and I had a period of down-and-up that lasted about 30 minutes, but there have been no interruptions for the last hour. I expect this will sort itself out within the next few days.

So I’m down to thinking that, if there *is *some sort of interference, it is extremely localized in my apartment, where it does not affect any of my neighbors (at least, tech support didn’t show any complaints from other Charter customers in my building. The only thing I can think of is that we connected an Amazon FireTV stick to the TV not long before the problem first started. But that has remained in use this entire time, right through the months of not having an issue.
Any clues as to what might be going on? I’m out of ideas.

2

Try disconnecting everything except the modem, router, and your PC. In my experience a local IP conflict can cause problems such as you describe - one machine claims an address, then the other one calls in and resets the connection, repeat every few minutes.

I also recommend you check your router’s log and see if you can identify an error or pattern there. Also, when the “internet” is out, are you still able to access your router through the direct Ethernet cable?

And if you are doing Ethernet over A/C then it might be an electrical issue.

~Max

3

I didn’t read the whole OP but I had a wifi router problem that was solved by configuring it to stay on a certain channel instead of letting it try to find find a quiet one.

4

sigh As is happens, about four hours ago, after fooling with every connection I could find, including plugging power supplies directly into a wall socket (in case there was something weird with the power strip) I found the problem, and it was indeed “interference”.
I hadn’t previously noticed that, due to changing weather, my wife had replaced a fan with a space heater, fairly close to the router. I unplugged the heater and moved it across the room, and voila, the problem has gone away. I going to assume that the heater’s electric motor was producing a magnetic field that was affecting the router. It would also explain why, for the last week or so, the problem had more or less disappeared during the day, but was reappearing at night - daytime had still been warm enough to not need the heater, but my wife was turning it on at night. But the local daytime temperature has dropped the last two days, so the heater was in use during the day and the internet problem came back during the day.
Now that I’ve figured this out, it explains why, the first time I had this issue, the problem suddenly seemed to “fix itself” - it was back in March, and the weather was still cool, but when it warmed up my wife put the heater away, removing the cause of the issue.
Anyway, thanks for reading :slight_smile:

5

That might be it, but a heavy-duty heater might also be overloading your power system (they are known to do this if left on for too long). If possible you would want your heater plugged in to a dedicated circuit - an outlet with its own switch on the circuit breaker. You don’t want it sharing a circuit with something like a router or, well anything really.

~Max

6

It’s now plugged into a different outlet, but it is, alas, the same circuit. Downside of an apartment that was built pre-WW2. There is one outlet in the kitchen with its own circuit, and another in the little passageway between the kitchen and the living room. Every other outlet and light fixture in this place are all on the same breaker. In order to have a window A/C or space heater upstairs (I refuse to use the built-in wall heater - those things scare me, and the summer heat makes this place unlivable without the A/C), I had to get a heavy-gauge extension cord, run it downstairs, and plug into the outlet in the passageway with its own breaker, just so that I could have heat without knocking out all the power. The wiring in this place is completely inadequate for a “modern lifestyle”. Not to mention the non-existent insulation.

Thankfully, my wife finally got her SSI-Disability approved, and the first “back pay” check she’ll get later this month will allow us to get out of here and into something newer ASAP.

7

Be careful with that extension cord! An electric space heater can easily use upwards of 1500W, and is probably designed for a 120V outlet. That means the load is going to be about 12.5A (1500/120=12.5). You have to mind the voltage drop - the longer the cord, the higher the amperage. The thinner the wire, the less amperage it can take before melting and starting an electrical fire.

You will want a heavy-duty extension cord of the shortest possible length. Heavy-duty like from the garden & outdoor section. You must check the tag on your extension cord for the amperage rating, but generally a 14 to 16-gauge cord will cover you for 25 feet up to 13A, I think you’ll need 12-gauge for 50 feet and 10-gauge for 100 feet.

Be safe, and realize that your heater probably has a big warning label that says DO NOT USE AN EXTENSION CORD.

~Max

8

Indeed. I discovered that the original cord I was using was getting hot (several years ago), so I went right out and bought the heaviest one I could find. I check it fairly regularly to see if it’s hot, and it’s stayed nice and cool.
I unfortunately don’t have much choice in this place. My apartment is on the very end of the building, with the big outside wall facing west. The outside of the wall is cinderblock, and as we discovered when Charter came in to reroute the cable and they ran it up through that wall from the basement, there is literally no insulation. It’s just plaster and lath applied directly to the cinderblock. In the summer, that west wall soaks up the sun for most of the day and radiates the heat directly into the apartment - the first summer I was here, I had my computer downstairs, and one night in July I looked at the thermometer and it was 95 degrees in my living room at 10:30PM. I packed up everything and set up my computer upstairs where I had the window A/C unit. And then in the winter, I touch the indoor surface of that wall, and it’s like touching a block of ice. I’m going to be very happy to move out of here.

9

Yeah, I recently visited some ancient brick houses in Virginia and it was quite hot. I’m used to heat but I definitely understand the need to have air conditioning and insulation. Glad to hear your house isn’t melting (from an electrical fire or the weather), and good luck with the move!

~Max

10

This is great! Nice job on figuring out the space heater. I HATE problems like that.

11

I agree that EMI is pretty unlikely in this case, though one never knows. Since the heater was on the same circuit before and after the problem got solved, I’d bet the problem was the main output of your heater: heat.

Most routers don’t have a ton of thermal margin. The heater may have heated the router beyond its Tmax, causing it to shut down and reboot. This can happen even indirectly; it doesn’t take much.

I had an old Linksys WRT-54g that I configured and gave to my dad. It was locking up regularly, despite having run flawlessly for me. It turned out that my dad moved it from a shaded windowsill to beneath his desk. That wouldn’t be so bad, but he put it right on top of his computer’s case, which was warmish to the touch. I moved the router back to the windowsill and the problem vanished. As always, YMMV.

12

Certainly possible! In my setup, though, the router and modem were next to each other at the back of the shelf below the TV, and the heater was on the same shelf with the TV, more or less directly above the router, but toward the front of the shelf. So 16-18 inches apart, and the top shelf itself is 1-1/4 inch solid wood. When I started fiddling with things again yesterday, I picked up the heater and set it on the coffee table, so now it was three feet away and blowing away from the router, but the problem continued as before. It wasn’t until I moved it about 8 feet away that the issues stopped.
In any case, it’s been about 18 hours now with no more trouble :slight_smile:

13

Just want to mention I had a similar problem until I got a wireless adapter for my PC made by the same company that made the router. The old adapter, from a different manufacturer, was very unreliable.

14

sigh Tomorrow I am going to physically go to the Charter Spectrum office and insist they physically send somebody to try to figure this out. Calling tech support, wherever they’re physically located, doesn’t seem to solve anything. I suspect the remote tech support people can’t “see” anything past the last box on the line before the cables enter my building. I mean as far as telling if there are any outages, because they always say, “I’m not seeing any outages in your area”.

Remember how the problem instantly stopped after I moved the space heater away from the modem and router? That “fix” lasted maybe two weeks, but now it’s started back up again. Last night I went down to turn that space heater off to see if that helped, but it wasn’t on in the first place.
Given that the first time this issue came up I completely replaced both modem and router, and then it popped up again, in exactly the same way, with completely different modem and router, I strongly suspect it’s not a hardware issue at my end. And none of this nonsense happened during the six years I used their service before they rerouted the cables.

15

Yes, I too would have guessed either overheating the guts of the router, or the heater kicking in causes a momentary brown out - a voltage drop below what the router needs. Not sure what a small UPS (battery backup power supply) costs, but that might be an option to see if it helps. Is it possible you share a breaker with an adjacent apartment that could be causing brown outs with its own electrical heater? If the router is power sensitive, also, finding a bigger more powerful power brick with the same voltage output might be a good test. (Would imply bigger capacitors, less susceptible to momentary drops)

Does everything drop? Wifi and the wired connection? Can you connect to the router controls? Wired, do you lose connection to the router admin console when the router does its thing? Is it literally rebooting, or freezing and resuming? How long are these outages, or are they so fleeting that the only clue is the broken external IP connection? If you ping a Wifi device from the wired PC, does that also stop/drop when the interrupt happens?

16

“We need to put our modem, router and big server box somewhere out of sight. I know! Let’s cram it in that tiny interior closet with the tight-fitting door and no ventilation. What could possibly go wrong?”

17

I agree with others that job #1 is to figure out if your WAN connection is the problem or if it’s your wifi LAN. Sounds like you are fine when you connect directly to your modem and that Charter can verify the WAN status to the modem each time you call them. So let’s stick to the theory that it’s a wifi problem.

First thing I’d do is load a wifi scanner app on my cell phone or laptop. Cell phone is probably better, as it seems like we are investigating the laptop (and other devices) issues. The wifi scanner will show you exactly which SSIDs are in your immediate areas, which channels they are using, and what their relative strengths are. If you temporarily turn off the cell phone’s power management, you can keep the phone near you as you work and get a sense of what is happening over time.

First thing to look for is whether you are sharing a channel with another network or device. My own Roku unit loves to share the same channel as my home LAN and the Roku signal is much stronger than my router signal at the location where I normally use my laptop. Selecting an unused channel for your router and permanently assigning it may cure this.

Second, keep an eye on the signal strength. Is it dropping low or disappearing periodically? Are you seeing a “new” SSID appear from time to time and does the router then change channels?

I suspect that SOMETHING is stepping on your wifi LAN. Getting a baseline can be a big help. In my case, I identified some really strong (unknown) SSIDs popping up from time to time. After watching for a couple days, I switched my router to a channel that seemed to be rarely used and told it “Stay!” No problems since.

18

Since I’m not going to be home when the service tech comes by, I typed up and printed out a detailed list of everything I’ve seen and done myself with this mystery:

–
ISSUE: Internet repeatedly dropping and coming back up.

First occurred a few months ago. Traded in old modem for new one, problem continued. Purchased new router, problem stopped, thought it was solved.

Problem reappeared 2-3 weeks ago, with the new modem and router; phone tech support cannot see any indication of service interruptions. The yellow cable connecting the modem to the router is also new.

NETWORK: Upstairs Windows 10 PC connected to router via wired Ethernet. Everything else (2 cell phones, Windows 10 laptop, TV) connected via WiFi. Upstairs Mac powered off and not connected to network. The TV itself does not have WiFi - it’s signal comes via an Amazon Fire Stick. The service interruptions affect all devices simultaneously, whether wired or wireless, so it is not specifically a WiFi issue.

Phone tech support, when this problem first started a few months ago, suggested possible interference from other nearby WiFi (neighbors, businesses). While I can detect a very long list of nearby WiFi networks, the problem is still happening at 3:00AM when I imagine most of those networks aren’t seeing a lot of activity.

STEPS I’VE TAKEN:
At suggestion from tech support, disconnected the router from the modem and plugged Ethernet cable directly into the modem. Tested on upstairs PC for 30 minutes, had no service interruptions. Restored previous connections, and issues resumed. This led me to suspect that slight “flickers” in the signal are enough to make the router think it has lost the connection, but the “flickers” aren’t enough to knock my PC offline when plugged directly into the modem. I have no way to verify this, however.

Suspecting possible magnetic interference from nearby space heater’s motor, I moved the heater across the room to its present location. Problem immediately stopped … then resumed 2 days later.

Suspecting space heaters powering up may be causing a momentary power dip, I turned off my upstairs heater, but found that the downstairs heater was already off. Problem continued.

Considered that the power strip supplying the modem and router might be flaky, I replugged both directly into the wall socket. This did not solve it.
Considered that my PC’s antivirus software’s network scans might be causing interruptions. Disabled that feature, and also disabled the AV software’s firewall (still have Windows Defender’s firewall up, and of course the router itself has a firewall, so figure I’m safe without a third). No luck.

Considered that the modem might be overheating due to being close to the walls that get a lot of sunlight. Directed a fan at the modem to cool it. Didn’t solve anything.

I’ll also add that my wife’s caregiver said that she is experiencing the exact same problem at her home.

My modem and router are in roughly the same location they’ve been in for 7-1/2 years; no issues until a few months ago. I’ll also note that, until I got married I never used that room and had no A/C in it, and it got quite warm in there during the summer (very old construction, poor insulation, and outside walls (closest to the modem and router) facing South and West. Plus, both times these problems have started up have been during cool weather.

19

UPDATE: Service guy came around today as promised. According to my wife, after a bit of poking around he determined that the problem is, in fact, in the cables before it gets to my apartment. He, however, was only an “inside the home” tech, so he put in the call for the heavy-duty guys to come around and fix the problem “within 24 hours”.