(2) VLANS VIRTUAL LOCAL AREA NETWORKS OPERATION

CONFIGURATION PROCESS

A VLAN (Virtual Local Area Networks Operation )requires a series of configuration steps in order to begin operating. Cabletron Systems VLAN aware SmartSwitches do not default to VLAN mode, and the VLAN operation must be configured and activated through software management.

1. Defining a Virtual Local Area Networks Operation
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) 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.

2. Assigning Ports to a Virtual Local Area Networks Operation
Now that a VLAN has been created, individual ports are given membership in the VLAN. This is accomplished through software management by associating a VLAN ID with each port on the VLAN aware switch. 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 any needed trunk ports to consider themselves members of every VLAN. The configuration of trunk ports is very important in multiswitch VLAN configurations where VLAN membership applies to users across several switches.

3. Customizing the Virtual Local Area Networks Operation’s Forwarding List
Once the ports that will participate in the VLAN have been associated with a VLAN ID, the VLAN Forwarding List can be customized. The information in the Forwarding List tells the VLAN aware switch what ports are eligible to forward traffic for that particular VLAN.

4 Customizing the Port’s Egress List
When the VLAN Forwarding List is fully configured, the Egress List for each port may be customized if needed. The entries in the Egress List allow traffic classified into specific VLANs to be transmitted out the port.

5 Setting the Operational Mode
Once the VLANs are in place, the operation of the switch is dependent upon the method of operation specified by the Administrator. All port based VLAN switches can be set to one of two operational modes: Open and Secure. The mode configuration of a switch determines how the switch handles the frames that it receives.