The magic Google phrase to search for would be "Chromebook vpnc" - 'vpnc' is a Cisco VPN client that also happens to work with GlobalProtect gateways (you have to turn XAUTH on in the Gateway as well... there's another forum thread on here that goes over it, search for 'vpnc')
Unfortunately the results I'm finding for official support for IPSec from Google don't look promising:
"Implementation of OpenVPN support is already in progress. vpnc, if I had to guess, is not likely to be implemented (because more advanced encryption options on Cisco VPNs causes vpnc not to be redistributable as a binary, for obscure legal reasons)."
But if you're OK with doing it yourself, another blog post DOES look very promising:
The "right way" to do this would be with a GUI, with NetworkManager or some such frontend. I'm not sure that a GUI VPN client of that nature is available for the Chromebook platform unfortunately
Click Accept as Solution to acknowledge that the answer to your question has been provided.
The button appears next to the replies on topics you’ve started. The member who gave the solution and all future visitors to this topic will appreciate it!
These simple actions take just seconds of your time, but go a long way in showing appreciation for community members and the LIVEcommunity as a whole!
The LIVEcommunity thanks you for your participation!