Policy-based routes let you specify a next hop based on the packet’s protocol and source IP address in addition to the destination IP address. In this case, traffic is redirected to an internal passthrough Network Load Balancer which enables the insertion of appliances such as firewalls into the path of network traffic as policy-based routes are evaluated before other routes are evaluated. Note that other than policy-based routes, no other route type is allowed to have a destination that matches or fits within the destination of a local, peering, or  Network Connectivity Center subnet route.