Zwift ride is causing internet connection drops / disconnects / lost on provider side


I joined Zwift recently. Since the beginning I have the issue, that during a rife the whole internet connection is dropped / lost on the provider side. Means, my internet box (router) is flashing red light, indicating that it lost connection to the internet and is trying to reconnect.
Initially I turned-off and powered-on the internet box and once it was connected, I was able to go on with the current ride.
Now I realized, that there is a faster way to reconnect by unplug the cable from the wall and reconnect. This triggers also a reconnect of the internet box, but without reboot.

May provider is already trying to figure out, why it disconnects, but no results so far.

I’m bit surprised that ZWIFT rides are causing such an issue and wondering if there is a solution for it and what exactly is causing those internet connection drops on provider side.
btw. this happens only during a ride. If you just join a world and you don’t start to ride, then it runs forever without a connection lost, but once you start, latest after 20-30 minutes it happens.
Today I lost three times the connection within 30 minutes.

Thank you in advance for oyur inputs.


Wow, that’s a pretty strange problem. It’s definitely something for your ISP to look at, especially if your router is provided by the ISP. Faulty router, perhaps?

Only ZWIFT rides are causing this. Other apps which requires a higher bandwith like Flight Simulator 2020 work well. I would assume, that something during ZWIFT Rides is causing such issues, and as I saw couple more forum entries where people have problems with saving rides while they have lost their internet connections. Therefore I believe it is not only my provider and that ZWIFT has maybe some buggy behavior.

No-one has reported their modem/router disconnecting though, that’s a very different issue.

Maybe they haven’t checked their router and just saw, that other riders disappeared. And in the background their router rebooted by themselves, which would lead to a non-re-connected WLAN connection :wink:
My next test would be using my iPhone as Hotspot using 4G/5G network connection.
Let’s see if that is more stable.

Zwift uses some unusual ports, that your other apps won’t be using. Most likely this is exposing some bug in your router that is causing it to disconnect.

Yes, try via your phone. That’ll work fine.

Quick update here.
My provider reduced the speed from 470Mbit/s down to 370Mbit/s and they had a minor Firmware update for my router. For time being it is working.
Provider will now increase the speed slowly again. Let’s see if the issue comes back again.
Still unclear why only rides in ZWIFT caused an interreuption of the whole internet.

Hi Mladen,
Any update on this topic?

I seem to have the same issues with my equipment. It doesn’t happen every ride, sometimes I ride for multiple hours without connection loss and sometimes I lose signal after some minutes.

Have to analyze the log files but to me it seems that I always lose internet connection (just the Zwift application). Other apps on PC still have internet connection and also my mobile still has internet. After losing internet connection other riders disappear and I lose power, cadence and HR connection. After some minutes everything reconnects and continues to work.

Could be a similar problem to yours?

Thank you,

Hi Roman

Sounds to be a different issue, as I a lost the whole internet, means no other browser, device, app had any internet connection.

The issue with disconnected Smart Trainer or Heart Rate Monitor I have as well, but only on my windows PC, but when losing that connection, I can still see to other riders.

Personally I had the best experience so far with the iPad or iPhone. My Apple Macbook Pro had the issue, that the Smart Trainer wasn’t in sync with Zwift, so I did not further test.

Currently it seems to be stable with iPad, but my Provider (Swisscom) has still a limitation on a my connection, as my bandwidth is still at 380 Mbit/s and not at the maximum of 470 Mbit/s. So waiting for the increase again.
Either the Firmware Update of the Router or throttling down the internet speed was helpful for me.
Updates will follow.

Looks like the firmware update of the router di not fix the issue.
What seems to fix it, is the increase of the attenuation of my Download from 6 to 9 dB while Upload remained at 6 dB.
That means my maximum Download speed reduced from 470 Mbps to 420 Mbps, but it makes it much more stable. And the IPTV has been improved as well, as the flickers stropped.

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I just started to get this “connection disconnected” problem after Nov upgrade.
Only Zwift losing connection to server.
Spotify, iptv, youtube etc works perfect without any issue. Zwift should have a reconnect once it lost connection imho

Sound like you have a different kind of issue.
Sadly mine still exists.
During ZWIFT riding sessions - horrible when it happens during races - the whole Internet connection gets lost. Means, no Spotify, no IPTV nor YouTube.
What I have seen is, that when I connect to WebGUI of my Router while disconnected from the Internet, it says that DNS servers have issues. When checking the DNS server settings they are empty.
After reboot of the Router they appear again. I also changed from Automatic to Manual without success. I changed the DNS servers also to Goggle’s DNS servers, also no success.
It looks like, that zwifting is deleting the DNS server setting or at least it triggers with its behavior that deletion.
Next Test will be to deactivate DNS Cache on the Router.

It sounds to me that your router is either faulty or just a very poor one, and that it’s the source of your problem. What sort of router is it?

The one from my Provider.
Here a link to that router.

(Sadly I can’t paste a link, but google for “Swisscom Internet Box 3”)

Router has been replaced already three times.
Before I had also the Internet Box 2 and this one is the Internet Box 3.
btw. I have not Fiber Connection yet.
I do not understand why zwifting is causing that. I had no issue when I just opened the Zwift App and being in Watopia standing still.

Maybe I will also do an electromagnetic field check, if the Wahoo Bike causes it.
What it would be against it is, that using my iPhone as Private Hotspot over 5G is working fine and the Internet Connection n the Router remains.

There is no way that one app should be able to take down your whole internet connection. Some combination of what Zwift is doing is messing up either your router or something at your ISP. This must be incredibly frustrating, I’m sure, but it can’t be Zwift’s fault. As you say, it works fine over 5G.

Is it possible to put your ISP’s router into a modem mode and use a different router?

That isn’t that easy as I have a WLAN extender from Swisscom (provider) on the upper floor, which communicated via a hidden, dedicated WLAN 5GHz connection with the router, as our IPTV Box from Swisscom is connected via Ethernet to that WLAN Extender. And buying now a proper Router/Mesh equipment just for that test is not worth.

And I can’t remember that I have seen such a Modem Option. Might be that I would have to disable all the features used by a Router.

Mladen, sorry to hear about these issues.
I have something similar here… since some last 6 months my internet connection on my MacBook Air is being dropped (no connection at all) once I launch Zwift app. Sometimes it drops immediately and I can’t even log in to app, sometimes it ‘remains’ for a minute or two and I’m able to log in, chose the course, but then I’m the only one on the course and do not see other riders.
Tried to identify the issue either with my ISP or firewall or antivirus (blocks some connections??), turned off ALL firewall etc protection services - nothing, same happens every time. Close zwift app, and the internet is back.
Any chance someone from Zwift support would pick up this issue?

You should try to speak with your ISP.

Cmon… It started something like 6 mths ago after another update pack. Changed the ISP actually 2 mths ago (one mobile provide to another) - not because of this issue -, however same ■■■■

I sent an e mail to Zwift support in December . They acknowledged that there was a problem and said that I must wait for a fix to be downloaded : to date the problem still exists. I am really surprised that Zwift have not been able to sort this.