Understanding Filter-Based Forwarding
For IPv4 or IPv6 traffic, you can use firewall filters in conjunction with virtual routing instances to specify different routes for packets to travel in their networks. This feature is called filter-based forwarding (FBF), and is also known as policy-based routing (PBR).
You might want to use FBF to route specific types of traffic through a firewall or other security device before the traffic continues on its path. You can also use FBF to give certain types of traffic preferential treatment. For example, you might want to ensure that the highest-priority traffic is forwarded over a 40-Gigabit Ethernet link.
To set up FBF, you specify a firewall filter match condition and action and then specify the virtual routing instance to send packets to.
You can create as many as 128 filters or terms that direct packets to a given virtual routing instance.
(QFX5100, QFX5110, QFX5200 switches) Starting in Junos OS Release 19.1R1, filter-based forwarding is supported on IPv6 interfaces (ingress direction only).
Benefits of Filter-Based Forwarding
Allows you to have more control over load balancing than dynamic routing protocols typically provide.
Change History Table
Feature support is determined by the platform and release you are using. Use Feature Explorer to determine if a feature is supported on your platform.