Which switch function reads the frame and uses the MAC address table to decide the egress interface for the frame?

The forward/filter function of a switch is used to look up the destination MAC address in a MAC address table and decide the egress interface for the frame. If the MAC address is not in the table, the frame is forwarded out all of the interfaces. When the client responds, its source MAC address will be recorded in the MAC address table for future lookup. Address learning is performed when frames enter into the interface; the source address is written to the port it is observed on. Loop avoidance employs Spanning Tree Protocol (STP) to block redundant links to prevent loops. Frame flooding is a default action of the forward/filter process when a destination frame is unknown.