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AnyConnect client installation or upgrade errors

NOTE: Before installing the Cisco AnyConnect VPN Client you will need Admin rights to your machine. You may have to arrange this through your relevant local IT support.

The installation (or upgrade if an earlier version is already installed) of the Cisco AnyConnect Client should be an automated process when using the web VPN gateway. However in some instances you may be asked to download the client software and install it manually.

In some cases the installation only partially succeeds, or in the case of upgrading can fail. Try uninstalling the AnyConnect client (if installed) first and then try repeating the installation process again.

TUN/TAP Error Message with Mac OS X 10.5

During the installation of the AnyConnect client on a Mac OS X 10.5, the following error message can appear:

"A version of the TUN virtual network driver is already installed on this system that is incompatible with the AnyConnect client. This is a known issue with OS X version 10.5 and prior, and has been resolved in 10.6. Please uninstall any VPN client, speak with your System Administrator, or reference the AnyConnect Release Notes for assistance in resolving this issue."

Versions of Mac OS X earlier than 10.6 do not include a TUN/TAP virtual network driver, so the AnyConnect client installs its own. However, some software such as Parallels (software that manages data cards), and some VPN applications install their own TUN/TAP driver. The AnyConnect client installation software displays the error message above because the driver is already present, but its version is incompatible with the AnyConnect client.

This is resolved in Mac OS X version 10.6 because it provides the version of the TUN/TAP virtual network driver the AnyConnect client requires.

To install the AnyConnect client, you must remove the TUN/TAP virtual network driver.

Note: Removing the TUN/TAP virtual network driver can cause issues with the software on your system that installed the driver in the first place.

To remove the TUN/TAP virtual network driver, open the console application and enter the following commands:

sudo rm -rf /Library/Extensions/tap.kext
sudo rm -rf /Library/Extensions/tun.kext
sudo rm -rf /Library/StartupItems/tap
sudo rm -rf /Library/StartupItems/tun
sudo rm -rf /System/Library/Extensions/tun.kext
sudo rm -rf /System/Library/Extensions/tap.kext
sudo rm -rf /System/Library/StartupItems/tap
sudo rm -rf /System/Library/StartupItems/tun

After entering these commands, restart the Mac, then try re-installing the AnyConnect client.