Dell N2000 Series, Configuration Manual

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Configuring VLANs
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Configuring VLANs
This chapter describes how to configure VLANs, including port-based
VLANs, protocol-based VLANs, double-tagged VLANs, subnet-based VLANs,
and Voice VLANs.
The topics covered in this chapter include:
• VLAN Overview
• Default VLAN Behavior
• Configuring VLANs (Web)
• Configuring VLANs (CLI)
• VLAN Configuration Examples
VLAN Overview
By default, all switchports on a Dell Networking N2000, N3000, and N4000
series switches are in the same broadcast domain. This means when one host
connected to the switch broadcasts traffic, every device connected to the
switch receives that broadcast. All ports in a broadcast domain also forward
multicast and unknown unicast traffic to the connected host. Large broadcast
domains can result in network congestion, and end users might complain that
the network is slow. In addition to latency, large broadcast domains are a
greater security risk since all hosts receive all broadcasts.
Virtual Local Area Networks (VLANs) allow you to divide a broadcast domain
into smaller, logical networks. Like a bridge, a VLAN switch forwards traffic
based on the Layer 2 header, which is fast, and like a router, it partitions the
network into logical segments, which provides better administration, security,
and management of multicast traffic.
Network administrators have many reasons for creating logical divisions, such
as department or project membership. Because VLANs enable logical
groupings, members do not need to be physically connected to the same
switch or network segment. Some network administrators use VLANs to
segregate traffic by type so that the time-sensitive traffic, like voice traffic, has