Redundant member interface selection

[austar]

Hi experts, 

What is the selection mechanism of active interface over other members in a redundant interface?

how to manual configure the active interface of a redundant interface?

Thanks

[mgoswami]

The interface which has the lowest priority will be the Primary interface.

https://community.fortinet.com/t5/FortiGate/Technical-Tip-Redundant-Internet-connection-without-load...