Prerequisites For Private Vlans; Guidelines And Limitations For Configuring Private Vlans; Secondary And Primary Vlan Configuration - Cisco Nexus 7000 Series Configuration Manual

Configuring Private VLANs Using NX-OS

Prerequisites for Private VLANs

Private VLANs have the following prerequisites:
• You must be logged onto the device.
• If necessary, install the Advanced Services license and enter the desired VDC.
• You must enable the private VLAN feature.

Guidelines and Limitations for Configuring Private VLANs

Private VLANs have the following configuration guidelines and limitations:
• You must enable private VLANs before the device can apply the private VLAN functionality.
• You must enable the VLAN interface feature before the device can apply this functionality.
• Shut down the VLAN network interface for all VLANs that you plan to configure as secondary VLANs
• Isolated trunk configuration on any FEX port is not compatible with the global configuration system

Secondary and Primary VLAN Configuration

Follow these guidelines when configuring secondary or primary VLANs in private VLANs:
• You cannot configure the default VLAN (VLAN1) or any of the internally allocated VLANs as primary
• A primary VLAN can have multiple isolated and community VLANs associated with it. An isolated or
• Although private VLANs provide host isolation at Layer 2, hosts can communicate with each other at
• When a secondary VLAN is associated with the primary VLAN, the STP parameters of the primary
• For normal trunk ports, note the following:
before you configure these VLANs.
private-vlan fex trunk.
◦ Before applying the global configuration system private-vlan fex trunk, you need to remove any
isolated trunk configuration from FEX ports.
◦ After applying the global configuration system private-vlan fex trunk, isolated trunk configuration
on FEX ports is not supported.
◦ To use isolated trunk on FEX ports, you must remove the global configuration system private-vlan
fex trunk.
or secondary VLANs.
community VLAN can be associated with only one primary VLAN.
Layer 3.
VLAN, such as bridge priorities, are propagated to the secondary VLAN. However, STP parameters do
not necessarily propagate to other devices. You should manually check the STP configuration to ensure
that the spanning tree topologies for the primary, isolated, and community VLANs match exactly so
that the VLANs can properly share the same forwarding database.
Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x

Prerequisites for Private VLANs

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