Very slow internet connection after connecting to Cisco AnyConnect VPN

[JaydeepChoudhari78548]

I am using Cisco AnyConnect Secure Mobility Client version Version 4.5.03040 on my Windows 10 system to connect to our office VPN. From past few days I am experiencing a weird issue where my Internet speed is reduced by 96-97% after connecting to VPN. Without VPN my Internet connection shows 50Mbps on speedtest.net & after connecting to VPN it is reduced to less that 1Mbps. Trying to contacting to ISP didn't help. I want to know what kind of troubleshooting steps I can perform to point out the issue. My colleagues who uses same VPN are not facing this issue & also when I use my mobile internet, I don't see the issue. This issue occurs only when I use the broadband connection. Please help me troubleshoot the issue. I am not a expert in networking but hopefully I can provide more information if required. 

[RyanMcGowan06506]

We've got this problem too but it appears to be limited to connecting with AnyConnect via our wireless broadband internet connections (LTE) - not via various home/fibre internet connections. LTE connections are fine when not using AnyConnect. This started happening in a similar time frame to you as well Jaydeep.

[JaydeepChoudhari78548]

Ok. I am facing problem with my home broadband. There had been no issues past 2 years of usage. Not sure what is causing this issue now. 

[meagan.burt]

Hello everyone,

I just want to respond because we have had this issue for a very long time and we have done troubleshooting on it forever.  By chance I upgraded my vpn client as I was testing auto update on a new unit.  I installed the Cisco AnyConnect Secure Mobility Client version 4.10.04071.  After reboot, I happen to run the speed test again and....it I started getting speeds that matched what I get when not connected.  I was excited by the results but still skeptical...then my co-workers upgraded and had the same results.  We have tested many of our end users and this looks like it is a fix.  The problem does not appear to be in the headend but in the client itself.  We are now rolling out version 4.10.04071 to all of our users.

I am making this comment because I have researched this for a long time and have not seen anyone suggest a client update.  I want to share this with as many people as I can.