I am using Cisco AnyConnect on Ubuntu 18.04. The VPN sometimes got disconnected unexectedly. I try to reconnect, even quit the GUI, kill all process for programs under
NetworkManger service. No use, it still can't initiate the connection (no login dialog). What am I missing? I guess there is something with the
route is not cleaned up.
I got also this message from VPNGUI after a while:
The VPN connection failed due to unsuccessful domain name resolution
This article explains something about external DNS. I cleaned that up, and checked DNS information in Ehternet setting. Still couldn't get rid of the error.
This is the command that worked for me at last:
systemctl restart systemd-resolved.service