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There is an app for iPhone and iPad which some users have had success with. It is unsupported SLAC does not provide support for the app at this time, but you are free to make your own attempts to connect using it. Search the app store for "Cisco AnyConnect Client". Within the app, select "Add VPN Connection...". Enter vpn.slac.stanford.edu as the server address, this will be replaced with a list of the VPN servers that is automatically updated each time you connect.
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