Vlan Management Overview; Creating/Modifying Vlans - Alcatel-Lucent OmniSwitch 9900 Series Network Configuration Manual

Configuring VLANs

VLAN Management Overview

One of the main benefits of using VLANs to segment network traffic, is that VLAN configuration and port
assignment is handled through switch software. This eliminates the need to physically change a network
device connection or location when adding or removing devices from the VLAN broadcast domain. The
OmniSwitch VLAN management software handles the following VLAN configuration tasks:
•
Creating or modifying VLANs.
•
Assigning or changing default VLAN port associations (VPAs).
•
Enabling or disabling VLAN participation in the current Spanning Tree algorithm.
•
Displaying VLAN configuration information.
In addition to the above tasks, VLAN management software tracks and reports the following information
to other switch software applications:
•
VLAN configuration changes, such as adding or deleting VLANs, modifying the status of VLAN
properties (for example, administrative, Spanning Tree, and authentication status), changing the VLAN
description, or configuring VLAN router interfaces.
•
VLAN port associations triggered by VLAN management and other switch software applications, such
as 802.1Q VLAN tagging.
•
The VLAN operational state, which is inactive until at least one active switch port is associated with
the VLAN.

Creating/Modifying VLANs

The initial configuration for all OmniSwitch consists of a default VLAN 1 and all switch ports are initially
assigned to this VLAN. When a switching module is added to the switch, the physical ports are also
assigned to VLAN 1. If additional VLANs are not configured on the switch, then the entire switch is
treated as one large broadcast domain. All ports receive traffic from all other ports.
In compliance with the IEEE 802.1Q standard, each VLAN is identified by a unique number, referred to
as the "VLAN ID". The user specifies a VLAN ID to create, modify or remove a VLAN and to assign
switch ports to a VLAN. When a packet is received on a port, the VLAN ID of the port is inserted into the
packet. The packet is then bridged to other ports that are assigned to the same VLAN ID. In essence, the
VLAN broadcast domain is defined by a collection of ports and packets assigned to its VLAN ID.
The operational status of a VLAN remains inactive until at least one active switch port is assigned to the
VLAN. This means that VLAN properties, such as Spanning Tree or router interfaces, also remain
inactive. Ports are considered active if they are connected to an active network device. Non-active port
assignments are allowed, but do not change the operational state of the VLAN.
Ports can be statically assigned to VLANs. When a port is assigned to a VLAN, a VLAN port association
(VPA) is created and tracked by VLAN management switch software. For more information about VPAs,
see "Assigning Ports to VLANs" on page
OmniSwitch AOS Release 8 Network Configuration Guide
4-6.
December 2017
VLAN Management Overview
page 4-4