VLAN Management
228 Cisco 350, 350X and 550X Series Managed Switches, Firmware Release 2.4, ver 0.4
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Features Not Supported on Private VLAN Port Modes
The following features are not supported on private VLAN port modes:
• GVRP
• Voice VLAN OUI auto detection
• 802.1x port guest VLAN
• 802.1x port Dynamic VLAN Assignment
• Multicast TV VLAN.
NOTE Note the following clarifications:
• Port Security—MAC entries in the VLAN FDB table are flushed when the port is
unlocked.
• Port membership in a private VLAN is equivalent to port membership in 802.1Q
VLANs with regard to feature interaction limitations, for example:
- Port must not be added to a LAG/LACP.
- Port must not be configured as port monitor destination.
Required Resources
Since a private VLAN is composed of multiple 802.1Q VLANs, the system requires additional
resources for every secondary VLAN in a private VLAN. The resources for the following
features are allocated per VLAN within the private VLAN.
• Dynamic MAC Addresses—MAC addresses learned on primary VLANs are copied
to all community VLANs and to the isolated VLAN. MAC addresses learned on
isolated/community VLANs are copied to the primary VLAN.
• DHCP Snooping—A TCAM rule is required to trap DHCP traffic.
• ARP Inspection—A TCAM rule is required to trap ARP traffic.
• IP Source Guard—A TCAM rule is required to forward/drop IP traffic.
• First Hop Security—A TCAM rule is required to trap IPv6 traffic (when IPv6 source
guard is enabled).