Table of Contents
Advertisement
VLAN Switch Operation
2.3.3
Customizing the VLAN Forwarding List
Once the ports that will participate in the VLAN have been associated
with a VLAN ID (PVID), the VLAN Forwarding List can be customized.
By assigning a PVID to a port, that port is automatically placed in the
VLAN Forwarding List with a frame type of untagged. The information
in the Forwarding List tells the VLAN aware switch what ports are
eligible to forward traffic for that particular VLAN.
2.4
VLAN SWITCH OPERATION
IEEE 802.1Q VLAN switches act on the classification of frames into
VLANs. Sometimes, VLAN classification is based on tags in the headers
of data frames. These VLAN tags are added to data frames by the switch
as the frames are transmitted out certain ports, and are later used to make
forwarding decisions by the switch and other VLAN aware switches. In
the absence of a VLAN tag header, the classification of a frame into a
particular VLAN depends upon the configuration of the switch port that
received the frame.
The operation of an 802.1Q VLAN switch is best understood from a point
of view of the switch itself. To illustrate this concept, the examples that
follow view the switch operations from inside the switch.
802.1Q VLAN User's Guide
2-3
Advertisement
Table of Contents
