NS3503-16P-4C User Manual
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4.5 VLAN
4.5.1 VLAN Overview
A
Virtual Local Area Network
(VLAN) is a network topology configured according to a logical scheme
rather than the physical layout. VLAN can be used to combine any collection of LAN segments into an
autonomous user group that appears as a single LAN. VLAN also logically segment the network into
different broadcast domains so that packets are forwarded only between ports within the VLAN.
Typically, a VLAN corresponds to a particular subnet, although not necessarily.
VLAN can enhance performance by conserving bandwidth, and improve security by limiting traffic to
specific domains.
A VLAN is a collection of end nodes grouped by logic instead of physical location. End nodes that
frequently communicate with each other are assigned to the same VLAN, regardless of where they are
physically on the network. Logically, a VLAN can be equated to a broadcast domain, because broadcast
packets are forwarded to only members of the VLAN on which the broadcast was initiated.
Note:
1. No matter what basis is used to uniquely identify end nodes and assign these nodes
VLAN membership, packets cannot cross VLAN without a network device performing
a routing function between the VLAN.
2. The Managed Switch supports IEEE 802.1Q VLAN. The port untagging function can
be used to remove the 802.1 tag from packet headers to maintain compatibility with
devices that are tag-unaware.
Note:
The Managed Switch's default is to assign all ports to a single 802.1Q VLAN named
DEFAULT_VLAN
. As new VLAN is created, the member ports assigned to the new
VLAN will be removed from the DEFAULT_ VLAN port member list.
The
DEFAULT_VLAN has a VID = 1
.
