Private-Vlan Configuration Guidelines - Cisco 3032 Software Configuration Manual

Chapter 16 Configuring Private VLANs

Private-VLAN Configuration Guidelines

Guidelines for configuring private VLANs fall into these categories:
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Secondary and Primary VLAN Configuration
Follow these guidelines when configuring private VLANs:
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OL-12247-04
Secondary and Primary VLAN Configuration, page 16-7
Private-VLAN Port Configuration, page 16-8
Limitations with Other Features, page 16-9
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 see Chapter 14, "Configuring VTP."
modes.
With VTP version 1 or 2, after you have configured private VLANs, use the copy running-config
startup config privileged EXEC command to save the VTP transparent mode configuration and
private-VLAN configuration in the switch startup configuration file. Otherwise, if the switch resets,
it defaults to VTP server mode, which does not support private VLANs. VTP version 3 does support
private VLANs.
VTP version 1 and 2 do not propagate private-VLAN configuration. You must configure private
VLANs on each device where you want private-VLAN ports unless the devices are running VTP
version 3.
You cannot configure VLAN 1 or VLANs 1002 to 1005 as primary or secondary VLANs. Extended
VLANs (VLAN IDs 1006 to 4094) can belong to private VLANs
A primary VLAN can have one isolated VLAN and multiple community VLANs associated with it.
An isolated or community VLAN can have only one primary VLAN associated with it.
Although a private VLAN contains more than one VLAN, only one Spanning Tree Protocol (STP)
instance runs for the entire private VLAN. When a secondary VLAN is associated with the primary
VLAN, the STP parameters of the primary VLAN are propagated to the secondary VLAN.
You can enable DHCP snooping on private VLANs. When you enable DHCP snooping on the
primary VLAN, it is propagated to the secondary VLANs. If you configure DHCP on a secondary
VLAN, the configuration does not take effect if the primary VLAN is already configured.
When you enable IP source guard on private-VLAN ports, you must enable DHCP snooping on the
primary VLAN.
We recommend that you prune the private VLANs from the trunks on devices that carry no traffic
in the private VLANs.
You can apply different quality of service (QoS) configurations to primary, isolated, and community
VLANs.
Sticky ARP
Sticky ARP entries are those learned on SVIs and Layer 3 interfaces. They entries do not age
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out.
The ip sticky-arp global configuration command is supported only on SVIs belonging to
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private VLANs.
Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
Configuring Private VLANs
VTP version 3 supports private VLANs in all
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