Processing VLAN Frames
Earlier sections have introduced some of the major VLAN concepts and VLAN types. Now it is time to focus on how VLANs are configured and how switches process VLAN frames.
The cost of reducing broadcast and flooding overhead and controlling user access to parts of a LAN is that some extra processing must be performed by VLAN switches. This processing is controlled by configuration choices made by a LAN administrator.
The purpose of each configuration choice can be better understood after examining the steps that are followed when a switch processes a frame. These steps include
Examine each incoming frame and assign it to a VLAN. The rules controlling the assignment process are called ingress rules.
Check the filtering ...