Fundamental Switching Concept

The fundamental concept of switching refers to a device making a decision based on two criteria:

• Ingress port

• Destination address

The decision on how a switch forwards traffic is made in relation to the flow of that traffic. The term ingress is used to describe where a frame enters the device on a port. The term egress is used to describe frames leaving the device from a particular port.

When a switch makes a decision, it is based on the ingress port and the destination address of the message.