Chapter 7: Configuring Vlans - Linksys SFE1000P Administration Manual

Configuring VLANs
VLANs are logical subgroups with a Local Area Network (LAN) which combine user stations and
network devices into a single unit, regardless of the physical LAN segment to which they are
attached. VLANs allow network traffic to flow more efficiently within subgroups. VLANs use
software to reduce the amount of time it takes for network changes, additions, and moves to be
implemented.
VLANs have no minimum number of ports, and can be created per unit, per device, or through any
other logical connection combination, since they are software-based and not defined by physical
attributes.
VLANs function at Layer 2. Since VLANs isolate traffic within the VLAN, a Layer 3 router working at
a protocol level is required to allow traffic flow between VLANs. Layer 3 routers identify segments
and coordinate with VLANs. VLANs are Broadcast and Multicast domains. Broadcast and Multicast
traffic is transmitted only in the VLAN in which the traffic is generated.
VLAN tagging provides a method of transferring VLAN information between VLAN groups. VLAN
tagging attaches a 4-byte tag to packet headers. The VLAN tag indicates to which VLAN the packets
belong. VLAN tags are attached to the VLAN by either the end station or the network device. VLAN
tags also contain VLAN network priority information.
Combining VLANs and GARP (Generic Attribute Registration Protocol) allows network managers to
define network nodes into Broadcast domains. The VLAN Management section contains the
following pages:
• Defining VLAN Properties
• Defining VLAN Membership
• Defining Interface Settings
• Configuring GVRP Settings

Chapter 7: Configuring VLANs

SFE1000P Gigabit Ethernet Switch Administration Guide
Chapter
7
51