Configuration Process
13-8 VLAN Operation and Network Applications
Switches
In order to configure a group of stations into a VLAN, the stations must be connected to
VLAN-aware switches. It is the job of the switch to classify received frames into VLAN
memberships and transmit frames, according to VLAN membership, with or without a VLAN Tag
Header.
13.6 CONFIGURATION PROCESS
Before a VLAN can operate, steps must be performed to configure the switch to establish and
configure a VLAN. Enterasys Networks VLAN-aware switches default to operate in the 802.1Q
VLAN mode. However, further configuration is necessary to establish multiple logical networks.
13.6.1 Defining a VLAN
A VLAN must exist and have a unique identity before any ports or rules can be assigned to it. The
Administrator defines a VLAN by assigning it a unique identification number (the VLAN ID), a
filter database association, and an optional name. The VLAN ID is the number that will identify
data frames originating from, and intended for, the ports that will belong to this new VLAN.
13.6.2 Classifying Frames to a VLAN
Now that a VLAN has been created, rules are defined to classify all frames in a VLAN. This is
accomplished through management by associating a VLAN ID with each port on the switch.
Optionally, frames can be classified according to layer 2/3/4 information contained in the frame.
At the same time, the Administrator configures the trunk ports that need to consider themselves
members of every VLAN. The configuration of trunk ports is very important in multiswitch VLAN
configurations where a frame’s VLAN membership needs to be maintained across several
switches.
13.6.3 Customizing the VLAN Forwarding List
Each port on a VLAN-awareswitch module has a VLAN forwarding list that contains, as a
minimum, the Port VLAN Identifier (PVID) of the VLAN configured. Additionally, the Port
VLAN Forwarding List of each port can be configured to allow any number of VLANs to be added
to its list. In the case of GMRP (dynamic VLANs), the list can have VLANs added and deleted by
the switch as directed by the protocol.
NOTE: The actual steps involved in VLAN configuration using Local Management are
presented in Section 13.8. This brief section describes the actions that must be taken in
very general terms, and is intended only to aid in the Administrator’s understanding of
VLAN switch operation.