Three Switch Functions at Layer 2

Three Switch Functions at Layer 2
There are three distinct functions of layer 2 switching:
Address learning
Layer 2 switches and bridges remember the source hardware address of each
frame received on an interface and enter it into a MAC database.
The forwarding and filtering decision
When a frame is received on an interface, the switch
looks at the destination hardware address and looks up the exit interface in the MAC database.
Loop avoidance
If multiple connections between switches are created for redundancy, network
loops can occur. STP is used to stop network loops and allow redundancy.
These functions of the layer 2 switch—address learning, forward and filtering decisions, and
loop avoidance—are discussed in detail in the following sections.