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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
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Chapter 18 Configuring Private VLANs
Configuring Private VLANs
Tasks for Configuring Private VLANs
To configure a private VLAN, perform these steps:
Step 1 Set VTP mode to transparent.
Step 2 Create the primary and secondary VLANs and associate them. See the “Configuring and Associating
VLANs in a Private VLAN” section on page 18-9.
Note If the VLAN is not created already, the private-VLAN configuration process creates it.
Step 3 Configure interfaces to be isolated or community host ports, and assign VLAN membership to the host
port. See the “Configuring a Layer 2 Interface as a Private-VLAN Host Port” section on page 18-11.
Step 4 Configure interfaces as promiscuous ports, and map the promiscuous ports to the primary-secondary
VLAN pair. See the “Configuring a Layer 2 Interface as a Private-VLAN Promiscuous Port” section on
page 18-12.
Step 5 If inter-VLAN routing will be used, configure the primary SVI, and map secondary VLANs to the
primary. See the “Mapping Secondary VLANs to a Primary VLAN Layer 3 VLAN Interface” section on
page 18-13.
Step 6 Verify private-VLAN configuration.
Default Private-VLAN Configuration
No private VLANs are configured.
Private-VLAN Configuration Guidelines
Guidelines for configuring private VLANs fall into these categories:
Secondary and Primary VLAN Configuration, page 18-6
Private-VLAN Port Configuration, page 18-8
Limitations with Other Features, page 18-8

Secondary and Primary VLAN Configuration

Follow these guidelines when configuring private VLANs:
If the switch is running VTP version 1 or 2, you must set VTP to transparent mode. After you
configure a private VLAN, you should not change the VTP mode to client or server. For information
about VTP, see Chapter 16, “Configuring VTP.” VTP version 3 supports private VLANs in all
modes.