When I run my Mist wallet, the internet becomes unusable. I get a lot of timeout when browsing and page takes forever to be displayed.

I thought that maybe it was uploading too much to other people, so I installer the NetLimiter program. I saw that on occasion it was uploading at 50 KB/s, but most of the time it was very little like 2 KB/s or 0 KB/s.

What is odd is that the internet does not work even when the wallet is fully synced and I see no upload or download traffic from the wallet.

I got the message:


This problem also impact other computers, making me think that somehow the wallet just kill my router or my Wi-Fi.

Did any of you experience a similar issue? What could be the cause of the problem?

I am using Windows 10, my connection over WiFi is 70 Mbps in download and 59 Mbps in upload.

  • I also experience this with Parity (6MBit DSL, 8 GB Ram, SSD, i5). When I start my "blockchain" PC, Parity starts automatically. If I haven't started my "blockchain" PC for, let's say, 2 weeks...then the following happens from time to time: I am sitting on the couch with my wife watching prime movies. I go to my office, start my "blockchain" PC and go back to my wife. Suddenly, movie streaming stops... I go back to my office, quit Parity...and streaming continues :-). This is not a real answer, but it shows the problem also exists beyond Mist and Geth. Jul 4, 2017 at 8:15
  • Maybe your internet provider. I use fios 75Mb with almost no issues, sometimes movie streamming is only slightly affected.
    – Venus
    Jul 4, 2017 at 20:48

2 Answers 2


When you normally use your Internet to download a large file, that's not particularly taxing for all but the worst routers; you'll probably be more than happy in these situations. However, running an Ethereum node is not like your normal Internet use. You will have many connections open each doing very little. Your router's maximum total speed will likely peak with a few connections and drop off.

If your router manufacturer was... frugal, your router may not be happy with many simultaneous connections (or even a few) due to things like lack of router RAM, CPU, or plain bad code (I'm speculating about the exact causes). It also happens if you're making and/or breaking a lot of connections rapidly. If you can see what sockets are open (the number and churn), this can tell you if it might be the problem. A router might be able to do 100MBps with one connection and then drop to 10Mb (and lots of lag) with a few hundred connections. I don't think the ethereum packets are particularly small, but you might want to look at packets per second, anyway. You can run a network capacity testing tool on your LAN to see if your router is buckling under packet/connection load. Not sure if geth cleans up after itself nicely; that might cause abnormal loading (like leaving close-waiting sockets).

If your router isn't up to the task of routing and switching, you can tunnel your node through a VPN and/or try reducing the number of peers you connect to. This won't help, though, if you are constantly losing connections to peers (e.g., if your clock is not synchronized).


So, I figured out what my problem was. Port forwarding (port triggering on current router). You have to enable port forwarding on 30303.

Without port forwarding on my internet would die periodically. With port forwarding on I have no problem...

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