Enterasys 2200 Guia Do Utilizador

Configuration Process

VLAN Operation and Network Applications

Before a VLAN can operate, steps must be performed to configure the switch to establish and 
configure a VLAN. Cabletron Systems VLAN-aware SmartSwitches default to operate in the 
802.1Q VLAN mode. However, further configuration is necessary to establish multiple logical 
networks.

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.

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. 

Each port on a VLAN-aware switch has a VLAN forwarding list that contains, as a minimum, the 
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 

. 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.