DNS and Internet Issues

Buckle up, this one will take a while.

So I moved recently, and as a result, had to switch my ISP to Optimum. I'm WFH at the moment, so I got the nice, super-quick package, and they gave me an all-in-one modem/router. I connected my computer directly via ethernet cable, since, why wouldn't I?

And at first, all is well. But over the next few weeks, I notice a few odd things. First, the only light on the router/modem that appears to be on 90% of the time is the power light. Nothing else lights up.

I pay no heed because the internet's working.

Then, I begin having increasingly consistent DNS issues out of nowhere. There's no apparent rhyme or reason to them, suddenly, I'll just no longer be able to websurf as I usually do. What's extra-weird though, is that if I'm streaming something at the time (a movie, Spotify, even Discord chat), it'll keep going as normal. But otherwise, when these issues appear, generally, both my ethernet and WiFi connections crap out, so I can't access the web on my phone or stream on my PS4, along with my PC being unable to connect to anything.

This has intensified over the last few days, like, really, really badly. I can no longer reasonably count on my web browsers not to pop up a DNS error for six hours in a row anymore. And I've tried almost everything I found in guides onine to fix it.

- I've run several virus/malware scans (ESET NOD32 Antivirus and Malwarebytes)
- I've triple checked to make sure the drivers on my network card are updated
- I flushed the caches on Firefox and Chrome
- I've power cycled the router a sh*tload of times
- I've even flushed the DNS cache

Same problem keeps on cropping up.

Tonight, there was a development. Suddenly, the other lights on the modem (other than the power light) would turn on as my internet would completely drop out. No DNS error this time, I would get the little icon in my taskbar indicating I had no connection to the internet at all. Worse, cycling the power on the router several times didn't fix it. Lights (the internet light especially) would continue flashing, but I had no connectivity. Tried unplugging the ethernet cable, tried everything. Nada.

Eventually, the internet and WiFi lights flashed for a while before going solid. At that point (I checked), I could access the internet via the WiFi on my phone, but my PC was still reporting zero connection.

So I completely powered off my PC and then turned it back on, and, voila, I have an internet connection again. And once again, the only light on the router/modem is the power light.

I'm sure I've left off some parts here, but I'm just trying to figure out if I need to go over to Optimum and yell at them for giving me a sh*tty router (preferable) or, God help me if my network card is sh*tting the bed or my PC has some kind of godawful virus (not preferable).

I've tried just about everything, as I said. And what's extra weird is that this is a recurring issue, but not a constant one. I had days just this past week where I was connecting fine with no issues, but by Friday, things were sliding towards untenable. I've checked the cable connections, I've unplugged and re-plugged just about everything back in. At this point, I'm wondering whether or not the fact that the router/modem is plugged into the wall socket instead of my surge protector is the problem.

Mostly, I'm just hoping this is an issue with an ISP and NOT my computer, but I just need some advice.

EDIT: Also, I'm running Windows 10, if that helps at all.

EDIT v2: Or could it be that I have a LOT of tabs open? Like, between Firefox and Chrome, I have 40+ tabs open, although most of them are usually suspended? Also, PUP.Optional.WinYahoo. has been a recurring appearance in my Malwarebytes scans, although I haven't noticed any changes to my browser as a result. Maybe that?

EDIT v3: Recieved a text from Optimum this morning saying that an outage had been resolved, so perhaps my major issues yesterday were caused by that?

Go into your router settings and change the DNS to OpenDNS or Google DNS addresses?

You could also try disabling IPv6 on the router, a few years ago I had some weird problems like you describe until I did that.

I had fairly recurring issues where I'd lose connection temporarily for about 2-5 minutes. I could always get into my router fine and it would almost always say something along the lines of I needed to manually configure my DNS settings (despite them being configured just fine). Sometimes it'd say there was no signal from the isp, but using my phone I could check to see if my isp could see my modem or not, and it almost always could. Resetting my router usually appeared to fix it, but not always. After months of just resetting the router once or twice whenever it happened (which got to be almost a daily occurance), I got fed up and bought a new cable modem because mine was 8 years old by that point so I figured if any piece was going bad, it'd be that, so I'd start there. I haven't had the problem once in the two months since.
So what looked like a dns problem according to my router was actually my cable modem going bad.

Stengah wrote:

So what looked like a dns problem according to my router was actually my cable modem going bad.

Optimum set me up with a all-in-one modem/router, so I'm really hoping that's the issue.

It's been a week, and oddly, most of the week has been fine. I did another super-good DNS cache flush on Sunday, and it was good all day long, and through the week. All the correct lights on the modem/router were on as well!

That was, until Friday, when the issue popped up again.

As I said, I'm curious as to whether it's my PC or my router/modem, so when the issue happened again (and the WiFi crapped out along with it), I decided to try turning off my PC first.

To my fairly immense dismay, shortly after turning off my PC, I regained the ability to use the WiFi on my phone without getting the DNS error. I turned back on my PC, and things were fine.

Until a few minutes ago. DNS issues again, this time, I tried rebooting the router. I'm back online, but now I'm getting that weird thing again where only the power light is on on the router.

I'm going to try restarting my PC anyway, just to see what happens. I feel like it's 60/40 that it's probably an issue with the all-in-one router/modem, but I remain terrified that it's something with my motherboard.

Alright, so, the DNS issue happen twice (so far) today.

First time, I shut off the PC and checked the WiFi on my phone. My phone reported the same DNS issue for a good 4-6 minutes when I tried to websurf before the issue seemingly resolved itself and I was able to use the internet normally again.

Second time, I didn't shut off the PC. I unplugged the router, waited a good 5 minutes, then plugged it back in and all was fine.

Very odd. I'm inclined, based on the information so far, to believe it's an issue with my router, and not with my network card/motherboard. I hope.

Then, I begin having increasingly consistent DNS issues out of nowhere. There's no apparent rhyme or reason to them, suddenly, I'll just no longer be able to websurf as I usually do. What's extra-weird though, is that if I'm streaming something at the time (a movie, Spotify, even Discord chat), it'll keep going as normal. But otherwise, when these issues appear, generally, both my ethernet and WiFi connections crap out, so I can't access the web on my phone or stream on my PS4, along with my PC being unable to connect to anything.

I don't have any experience with Optimum, but back when I worked for Comcast this was pretty close to what you'd see in an upstream impairment. Streams wouldn't be affected as it's a downstream connection that, once successfully started, you're just receiving packets and not having to really transmit anything. But once you need to send out a request, it fails because your request never reaches the CMTS, and if the first request was a DNS call (which is pretty typical) then that's the error you get.

If you can get into the gateway to check the power levels, that would be the first thing I'd start with. Your upstream transmit power has a specific range it needs to be in. Too high and the gateway won't have the power to transmit back to the CMTS. Too low and your signal will get intermittently lost in the typical random noise you get in HFC networks at lower frequencies.

Is there a factory reset option on the router itself? Something to completely wipe all configuration/history? It's possible that there's persistent malware on the device itself, and a factory reset might clean it off.

Mmm, okay, I suspect this might be a me issue now.

I returned the router/modem this week and got a new one, and within 12 hours, had the same issue.

But now, having done a bunch of annoying research, I know how to flush my DNS cache, and that seems to solve the problem without having to restart the router/modem. So I'm guessing it's probably something with my Windows or my Ethernet card? Cuz' this is a spankin' new router/modem giving me the exact same issue.

I saw leapinggnome asked about changing the DNS servers in use, did you do that? Or are you still taking whatever nameservers are offered as part of your DHCP lease?

i will tell you, DNS resolution failure is reaally far down the stack to necessarily be related to a network card or motherboard specifically.

I'd be interested to know if you're still able to ping things (like 8.8.8.8), or what a traceroute to the same address looks like. If you can ping, but not resolve... that's more likely to be a failure of the DNS server itself. If you can't ping anything, then the traceroute might show you how far your traffic gets (Does it leave your network? Does it leave your ISP's network?)

Will look into this this weekend and get back to y'all.