I struggle every time I have to install cisco anyconnect vpn client on linux because you can't really download it unless you have a support contract. Since I'm a contractor, I need the program to communicate with multiple clients' networks. I'm sure I could track it down at one of my clients, but in a pinch I can usually find it to download from a university. Here are a couple of relevant excerpts about download and installation, copied in case the corresponding web page disappears.
===== (from UCI link)
Installing the VPN Client
Download the Anyconnect VPN client.
From the Terminal, navigate to the Downloads folder and unzip the file by typing [tar xzvf anyconnect-xxx.tar.gz]
NOTE: The *actual* file name will contain the name of the current version of the installer (e.g. anyconnect-linux64-4.5.03040-predeploy-k9.tar.gz)
A folder with the same name as the file will appear in the current directory. Open the folder and then go to the vpn directory, and once you are there type [./vpn_install.sh]
The VPN client will be installed on your system and the vpnagentd process will be started. This process will be started each time your system is booted.
NOTE: Ubuntu/Debian users should run this command to download a dependency for the VPN UI: [sudo apt-get install libpangox-1.0-0]
Starting the VPN Client
To start the client from the terminal, type [/opt/cisco/anyconnect/bin/vpnui]. Note: if you are not running a GUI, you can enter interactive mode by entering[/opt/cisco/anyconnect/bin/vpn]
NOTE: If you are using a desktop environment, you should be able to find the client in one of your menus as well (e.g. in a RHEL environment, look in Applications -> Internet).
In the “Connect to:” box, type vpn.uci.edu and press Return on your keyboard. Note: in interactive mode type [connect vpn.uci.edu]
In the “Group” menu that will appear, select the tunnel you wish to use, usually “UCI” or “UCIFull”. (See the differences in the Tunnels below.)
Enter your UCInetID and password in the appropriate boxes and click “Connect”.
You should get a banner box. When you do, click “Accept” and you are now connected.