Configuring Private Vlans" Section - Cisco 3020 - Catalyst Blade Switch Release Note

Configuring Private VLANs
This section describes how to configure private VLANs on the Cisco Catalyst Blade Switch 3020 for HP.
For complete syntax and usage information for the commands used in this chapter, see the command
Note
reference for this release.
The chapter consists of these sections:
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When you configure private VLANs, the switch must be in VTP transparent mode. See Chapter 14 in the
Note
software configuration guide, "Configuring VTP."
Understanding Private VLANs
The private-VLAN feature addresses two problems that service providers face when using VLANs:
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Using private VLANs addresses the scalability problem and provides IP address management benefits
for service providers and Layer 2 security for customers.
Private VLANs partition a regular VLAN domain into subdomains and can have multiple VLAN
pairs—one for each subdomain. A subdomain is represented by a primary VLAN and a secondary
VLAN.
All VLAN pairs in a private VLAN share the same primary VLAN. The secondary VLAN ID
differentiates one subdomain from another. See
OL-14130-02
Understanding Private VLANs, page 23
Configuring Private VLANs, page 27
Monitoring Private VLANs, page 36
Scalability: The switch supports up to 1005 active VLANs. If a service provider assigns one VLAN
per customer, this limits the numbers of customers the service provider can support.
To enable IP routing, each VLAN is assigned a subnet address space or a block of addresses, which
can result in wasting the unused IP addresses, and cause IP address management problems.
Release Notes for the Cisco Catalyst Blade Switch 3020 for HP, Cisco IOS Release 12.2(40)SE1 and Later
Figure 1.
Documentation Updates
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