When a host wishes to send a packet to a destination for the first time, it needs to determine an appropriate RIF.
Two frame types are used in order to find the route to the destination network segment.
Each frame has a maximum hop count, which is determined to be greater than the diameter of the network graph, and is decremented by each bridge.
The more a bridge is loaded, the less likely it is to take part in the route-finding process for a new destination as it will be slow to forward packets.
A switch with a faster backplane can be just as good for performance, if not for fault tolerance.