SD-WAN rules can use Border Gateway Protocol (BGP) learned routes as dynamic destinations.
In this example, a customer has two ISP connections, wan1 and wan2. wan1 is used primarily for direct access to internet applications, and wan2 is used primarily for traffic to the customer's data center.
The customer could create an SD-WAN rule using the data center's IP address range as the destination to force that traffic to use wan2, but the data center's IP range is not static. Instead, a BGP tag can be used.
For this example, wan2's BGP neighbor advertises the data center's network range with a community number of 30:5.
This example assumes that SD-WAN is enabled on the FortiGate, wan1 and wan2 are added as SD-WAN members in the virtual-wan-link SD-WAN zone, and a policy and static route have been created. See SD-WAN quick start for details.