Suddenly extreme latency

Fellow tech-heads I'm facing a big mistery at the moment that's driving me a bit off the rails. As the title says one day I started browsing the web and doing the usual surfing, streaming and gaming and I noticed that it was really sluggish. Basically the delay on every action is increased. I'm not talking about ping because using different ping tests, pinging google and all the services that to me look slow to respond report no packet loss and ping in pretty reasonable values for the distance. I'm using a Netgear D6200 modem/router and everything looks in check (except for the noise margin on the download that's around 9dB that I know being a not so good value).
I called my ISP and they say that everything from their servers to the modem is working good.
My home network is working as usual with no issues. I tried a couple of SMB transfer and I get the speeds I should get with my wired and wireless devices.
So, what do you think about my "story"? Is the modem/router to blame for the poor performance or my ISP is hiding something from me?

P.S. they don't even offer a fiber option where I live so slowing me down won't force me to upgrade to a pricier plan. I already pay for the highest tier plan they have.

I've noticed the same on my laptop and gaming computer. I attributed it to lots of traffic on the web but don't know enough about how things work. Also noticed it more when there is more than normal spam showing up on the forum I help moderate.
In for the knowledge....

If ping and packetloss isn't the cause - take a look at DNS - maybe your router (in case it does DNS forwarding) is getting a hang - or your ISPs DNS, or the one you use.

If every time your browser has to wait ages for the DNS reolution for all the (shit) that gets loaded criss cross around websites that can take a long time.

Give it a shot by manually using and (google! dns service) and see if that helps

In case you have linux on hand - try the dig command - dig and see how many ms the response took, than do dig @ and see what happened there - i got 1ms if its already cached and about 25ms on average if my local dns has to look it up externaly

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Thanks for the answer. I used openDNS to see if the situation got better but had no luck, same latency

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How old is your router?

I just recently had to get a new router. My old one was dropping DNS requests randomly, and that constituted lag badly. I eventually after testing and more testing only came up with replacing the router with a new one, and lo and behold my internet speeds were back where they were, and there was zero lag.

I don't know much about networking, but I can tell when a piece of equipment needs to be replace. Maybe this is your problem?

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probably your modem router combo is choking. Those things are usually terrible.

I had one for awhile until I got a proper dedicated router, disabled the 'router' part of my modem (so its just a modem) and then my sluggishness stopped.

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Traceroute your destination and see which hop has the highest latency, if your modem/router is around you, your ping shouldn't be more than 1ms. Reinstalling your network card's drivers never hurts. Run Wireshark on your interface and monitor your traffic, see if something weird comes up. If you haven't checked your modem/router's cpu and memory usage yet, do it now. No matter what you do, make sure your physical line is good first. You might be dealing with bad/long routes too, not much you can do about it I think, except talking to your ISP and see if they can do something about it.

I consider myself a magnet for such anomalies, suddenly I was having high pings, TCP ACKs were not going through, DNS was acting up with some domain names not being able to resolve. I nailed it down to my routes, for some reason my connection was being routed through a town 500 miles away lol.

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Thanks to all of you for the replies!

@Smerrills Mine is almost exactly 2 years old. Today I returned it and got the same but a brand new unit. Looks like there's no difference unfortunately.

@Dynamic_Gravity Why would it choke suddenly without adding any new device or doing something new? Has been working great for two years. It' can't say "nope, Imma get the hell out" and stop cooperating lol I've inspected it and the temps are as usual, the power brick is cold and there's no sign of throttling.

@ivailo My home LAN looks all good. The connection performs as expected and pages load times are the same on every PC that's connected through the RJ45 connector. Unfortunately I can't check the modem's CPU and RAM usage (or I don't know how to do it lol) but I've restarted it several times, making sure to unplug the power brick and using it to discharge completly the modem/router.
As I said in the OP even pinging google or servers looks good so the problem is not in my LAN.

If there is NO packetlos, NO overly huge roundtrip times (ping), every machine behind your gateway has the same problem - which is that surfing and accessing web resources feels slugish - it still feels like a problem with DNS.

Do you have any linux/mac os system, a VM or a LiveUSB with linux? - it would be realy insightfull as of how long DNS queries take for you - with domains that you visited regularely and such you have never visited - use something wired like (german Parlament) as that most likely is NOT in any DNS cache ^^

The hardware could be failing. I had a belkin that did basically what youre describing exactly a long time ago. That doesnt mean thats actually whats happening but you get the point.

What @Th3Z0ne is saying is probably the most logical explanation.

You could also try to turn off TCPIP auto tuning in windows with:

netsh interface tcp set global autotuning=disabled

you're may just be going bad. Mine was shit from day 1.

Thaks again for all the inputs and effort to help to everyone of you (:

@Th3Z0ne I can put up a Linux VM, what should I do next?

@Adubs and @Dynamic_Gravity Yesterday I returned the old unit and got a brand spanking new one (still the same product but has never been in use until now) so I think we can rule out the modem/router failing I guess.

UPDATE: everything looks fine now, the noise margin in the download raised from 9dB to 9.6dB and pages and downloads are behaving as they should. I didn't touch any parameter, I just went to bet yesterday and woke up today lol
What a joke of an ISP I'm paying, what a fucking joke!

the "dig" command lets you manually query DNS servers and check their response(s) and the time it took to generate said response(s).

dig -- will query your default DNS
dig @ -- will query the google DNS
dig @thednsyoulike -- will query the DNS server of your likings

That way you can check if there are significant differenses in the response time [ms] something between 2ms (local cache) and 25ms (google) is perfeclty fine - 100+ms feel sluggish as you described.

If you had no packet-loss the slight increase in SNR should not be he factor - but it is good that your SNR increased which gives you a nicer more stable signaling.

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hey, is is hot where you live. Like is it summer? what was the weather like yesterday?

yes this is important for troubleshooting


@Th3Z0ne I've run the test and there's no significant different between the ISP DNSs and the Google ones. I around the 2 to 3 ms difference in favour of Google. The problem is swinging back and forth with no particular pattern.

@Dynamic_Gravity It's spring, the highest temp under the sun it's 20°C. Inside the temp is never above 21°C until summer strikes lol The modem/router it's slightly warm under my cold hands.

Ok, than DNS is pretty much ruled out - do the test again when it feels sluggish again.
Now that we have ruled out packet-loss, DNS and datarate it becomes pretty tough to find what it might realy be....

I know. You and everyone else that answered to me has been helping out a lot. Also when the problem occurred the first thing I did was set the openDNS to see if something changed but still everything was going bad. My idea now is that my ISP is hooking up the fiber connection so this is making somehow the connection unstable, even if, when I asked, they said that there's no issue on the line because of that (I asked this directly).

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You could try an hook a PC directly to what ever (modem media-converter) you ISP provided so your can completely rule out you router

Maybe I wasn't clear in the OP about this. I'm using my own modem/router, it's a Netgear D6200 with both devices in one. My ISP is not providing any hardware, they just sent me configuration parameters to access the line.

P.S. yesterday I returned the two year old one I was using before to the store and got a new one (same model)

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I think I found some interesting things: I downloaded ping plotter and found out that first hop's IP that I'm going through is losing 40 to 50% of the packets according to this program, with peaks of 70%, just pinging Now the noise margin is back up again and my connection looks alright as before the issue.
What should I do now?

P.S. pinging it with the cmd reports 0 packet loss, wtf? Overall my connection is not loosing packets.

P.P.S. after setting up the google's DNS I'm seeing a 10 to 15% reduction of packet loss through the same hop. Also I'm jumping through 10 hops instead of 15.