Problems with Cisco AnyConnect VPN client driver error

Objective: To resolve Cisco AnyConnect VPN client driver error.

Problem(s):

There could be problems while connecting to your network after updating your AnyConnect client to the next/ latest version or simply even after a system update. The connection could be restricted only to a particular device in a network, while other devices can connect to the network from their physical and virtual machines easily.

When you try to connect to the network, AnyConnect would establish VPN session, initiate connection, examine system, activate VPN adapter, repair VPN adapter and end up showing Disconnect in progress, please wait in a few seconds. This is due to the Cisco bug ID CSCsm54689. This error will throw an error message "The VPN client driver has encountered an error".

While formatting your device, uninstalling and reinstalling the clients, or deleting ProgramFiles or ProgramData seem like possible solutions, they won't help resolve this error.

This problem can be solved using any of the following two techniques:

• Check your AnyConnect Networks adapter. Ensure the IPv6 protocol checkbox is unchecked.
  • The IPv4 and IPv6 protocols could have been checked by default in your system after a system update or the Cisco AnyConnect application update. Manually unselecting the IPv6 protocol resolves the client driver error in AnyConnect VPN. This is because the AnyConnect client doesn't support split-tunneling (ability to access dissimilar networks simultaneously) of the IPv6 traffic.
• If you had installed nmap (zenmap GUI) for Windows, it would have added an additional driver to the network interfaces.
  • Go to Cisco AnyConnect and open properties under Networks.
  • Disable or uncheck "NpCap Packet Driver".