Cabletron Systems 802.1Q Manual De Usuario

 

VLAN Operation

 

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 a protocol identifier contained within the 
frame. The order of frame classification priority is by VLAN Tag, a 
protocol match, and lastly the PVID. This combination of the switch 
port’s identification and the VLAN ID becomes the Port VLAN ID 
(PVID). 

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. 

 

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.