VRFs are always enabled and, by default, all routing is done in VRF 0. To use additional VRFs, assign a VRF ID to an interface. All routes relating to that interface are isolated to that VRF specific routing table. Interfaces in one VRF cannot reach interfaces in a different VRF.
If some traffic does have to pass between VRFs, route leaking can be used. See Route leaking between VRFs with BGP.
Enable Advanced Routing in System > Feature Visibility to configure VRFs.
Go to Network > Interfaces and click Create New > Interface.
Enter a value in the VRF ID field.