You are creating a new security policy using Juniper Apstra.

In Apstra 5.1, multitenancy is modeled using routing zones, which map directly to the network operating system concept of a VRF. A VRF is an isolated Layer 3 routing instance with its own routing table and forwarding context, and Apstra’s routing zone is the intent-based abstraction used to define and manage that isolation consistently across the fabric. Therefore, if your goal is to allow or deny traffic to or from a particular VRF, you must select Routing Zone as the security policy application point.

This choice enables you to express policy at the tenant boundary (VRF boundary) rather than at a single segment boundary. In EVPN-VXLAN data center fabrics, a tenant VRF commonly contains multiple virtual networks (VXLAN segments) and their associated IRB gateways on the leaf switches. Applying policy at the routing-zone level allows Apstra to compile intent and deploy enforcement consistently where traffic enters or exits that VRF context—typically as ACL constructs rendered as Junos firewall filters on the appropriate interfaces (for example, IRB interfaces for east-west controls or border interfaces for north-south controls).

By contrast, selecting Virtual Network targets a single segment (not the whole VRF), and Internal/External Endpoint targets specific endpoints or endpoint groups rather than the VRF-wide policy boundary. Hence, Routing Zone is the correct application point when policy scope is the VRF.