Private VLAN

• VTP doesn't propagate private VLAN information (transparent mode required)
• VLAN database mode is NOT supported
• Only the primary VLAN runs spanning-tree (community and isolated VLANs don't run their own STP instance)
• Strictly used for L2 filtering - L3 communication b/n hosts may still be possible

Example:

vlan 2
private-vlan primary
private-vlan association 4

vlan 4
private-vlan isolated

int fa0/1
switchport private-vlan host-association 2 4
switchport mode private-vlan host

int fa0/2
switchport private-vlan mapping 2 4
switchport mode private-vlan promiscuous

int fa0/3
switchport private-vlan host-association 2 4
switchport mode private-vlan host