Please, download the Administration Guide attached that is at the bottom of this article. The CSC GRE Cluster is for Virtual Platforms like VMware, Hyper-V, KVM, etc. 

CSC GRE Cluster with PriCPA for Netskope

With the CSC GRE Cluster you can protect your Public Traffic via Netskope and....

.... your Private Traffic with Private Cloud Private Access (PriCPA)