Exporting Flow Data and Virtual In-Path Deployments
In virtual in-path deployments, such as PBR, traffic moves in and out of the same WAN0_0 interface. The LAN interface is not used. When the SteelHead exports data to a flow data collector, all traffic has the wan0_0 interface index, making it impossible for an administrator to use the interface index to distinguish between LAN-to-WAN and WAN-to-LAN traffic.
You can configure the fake index feature on your SteelHead to insert the correct interface index before exporting data to a flow data collector.