E-Tree and Private VLAN Topology

Ethernet Private Tree (E-Tree) extends Shortest Path Bridging MAC (SPBM) to Private VLANs (PVLAN).

Transport within the SPBM network is achieved by associating the private VLAN with an I-SID. Flooded traffic from both promiscuous and isolated devices is transported over the same I-SID multicast tree and suppression for spoke-to-spoke traffic is done on the egress SPB Backbone Edge Bridge (BEB). This means the Private VLAN IDs are globally significant and must be the same on all BEBs.

The following list provides details for E-Tree and Private VLAN topology:

• E-Tree associates a Private VLAN with an I-SID.

  

  Note

  The same I-SID could be attached to a regular VLAN. In that case, all ports on the regular VLAN function like Promiscuous ports on the PVLAN.

• Other SPB BEBs can associate a regular CVLAN to the same I-SID that E-Tree uses.

  

  Note

  The CVLAN ID must match the primary PVLAN ID.

• CVLAN devices assigned to the same I-SID that E-Tree uses have Promiscuous connectivity within the segment.

The following figure shows a basic E-Tree network topology consisting of groups of private VLANs connected by the SPBM core network.

Sample E-Tree configuration

Private VLAN Port Types

The private VLAN port type is isolated, promiscuous, or trunk. If the port is a member of an MLT, then the port inherits the private VLAN type of the MLT.

In terms of network topology, the isolated port is considered a spoke. The isolated port, or spoke, does not communicate with any other isolated port in the network. The isolated port only communicates with the promiscuous ports, or hubs.

E-Tree and Private VLAN Limitations