Brocade Virtual ADX Switch and Router Guide (Supporting ADX v03.1.00) - Manual (Page 37)

Brocade Virtual ADX Switch and Router Guide 23
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Chapter
3
Configuring Virtual LANs (VLANs)
This chapter describes how to configure Virtual LANs (VLANs) on a Virtual ADX.
The “Overview” section provides basic information about VLAN options available on a Virtual ADX.
Following this section, other sections provide configuration procedures and examples.
To display configuration information for VLANs, refer to “Displaying VLAN information” on page 44.
Overview
This section describes the Virtual ADX VLAN features. Configuration procedures and examples
appear in later sections of this chapter.
Types of VLANs supported
You can configure the following types of VLANs on a Virtual ADX.
• Layer 2 port-based VLAN– a set of physical ports that share a common, exclusive Layer 2
broadcast domain
• IP subnet VLANs – a subset of ports in a port-based VLAN that share a common, exclusive
subnet broadcast domain for a specified IP subnet
When a Virtual ADX device receives a packet on a port that is a member of a VLAN, the device
forwards the packet based on the following VLAN hierarchy:
• If the port belongs to an IP subnet VLAN and the packet belongs to the corresponding IP
subnet, the device forwards the packet to all the ports within that IP subnet VLAN.
• If the packet cannot be forwarded based on either of the VLAN membership types listed above,
but the packet can be forwarded at Layer 2, the device forwards the packet on all the ports
within the receiving port’s port-based VLAN.
Layer 2 port-based VLANs
You can configure port-based VLANs on a Virtual ADX. A port-based VLAN is a subset of ports on a
Virtual ADX that constitutes a Layer 2 broadcast domain.
By default, all the ports on a Virtual ADX are members of the default VLAN. Thus, all the ports on
the Virtual ADX constitute a single Layer 2 broadcast domain. You can configure multiple
port-based VLANs. When you configure a port-based VLAN, the device automatically removes the
ports you add to the VLAN from the default VLAN.
Figure 1 shows an example of a Virtual ADX on which a Layer 2 port-based VLAN has been
configured.