Private Vlans

[praveennoc]

Can someone explaind about private Vlan's

whats is the difference between private vlan and normal vlan

[Robert Falconer]

The idea behind a private vlan is that the majority of the hosts cannot communicate with each other even though they are on the same subnet. 

Isolated ports can't communicate at L2 with any hosts unless a host is on a promiscuous port.

Hosts attached to promiscuous ports on the pvlan can communicate with all hosts. Typically this is a firewall or router so that traffic can exit the pvlan.

Community ports make subsets of the private vlan. They can only communicate with other community members and promiscuous ports.

[Adnan Mohammed]

Private Vlan: Also called as Port Isolation. where vlan contains switchports which are restricted and can communicate only through given uplink. PVlans contains many private ports or restricted ports or isloted ports and a single uplink.

Native Vlan: A native vlan is the untagged vlan on an 802.1q trunked switchport.  The native vlan and management vlan could be the same, but it is better security practice that they aren't.  Basically if a switch receives untagged frames on a trunkport, they are assumed to be part of the vlan that are designated on the switchport as the native vlan.