I have the Sonicwall Global VPN Client 4.10.2 and Windows 10. When I open the client on my computer, my internet slows to a crawl. It goes from ~90Mbps to <2Mbps, often less than 1Mbps. 

Inexplicably, this happens as soon as I open the client. Without even connecting to a VPN. The slowdown happens with or without the VPN connected. As soon as I shut down the client, my network speed goes back to normal. 

I've tried:

  • Removing my VPN profile - the client no longer even has a VPN to connect to
  • Reinstalling the Sonicwall client
  • Running Windows update through to completion
  • Running Lenovo System Update through to completion (I have a T460p)

I'm wondering if some hardware or software I have installed is incompatible with the Sonicwall client. 

Does this sound like a known issue? 


Evidently this is an issue with Windows 10. The solution is to disable Receive Segment Coalescing on the wireless adapter. Microsoft actually provides an automated fix as a download. It worked like a charm. I am back to my 50-80 Mbps download speeds with the VPN client running. 

Details can be found at the following Microsoft Answers link:

we need a windows patch installed