Primary, Isolated, And Community Private Vlans - Cisco Nexus 9000 Series Configuration Manual

Private VLAN Overview
Note
• Community port—A community port is a host port that belongs to a community secondary VLAN.
Community ports communicate with other ports in the same community VLAN and with associated
promiscuous ports. These interfaces are isolated at Layer 2 from all other interfaces in other communities
and from all isolated ports within the private VLAN domain.
Because trunks can support the VLANs that carry traffic between promiscuous, isolated, and community
Note
ports, the isolated and community port traffic might enter or leave the device through a trunk interface.

Primary, Isolated, and Community Private VLANs

Because the primary VLAN has the Layer 3 gateway, you associate secondary VLANs with the primary
VLAN in order to communicate outside the private VLAN. Primary VLANs and the two types of secondary
VLANs, isolated VLANs and community VLANs, have these characteristics:
• Primary VLAN— The primary VLAN carries traffic from the promiscuous ports to the (isolated and
community) host ports and to other promiscuous ports.
• Isolated VLAN —An isolated VLAN is a secondary VLAN that carries unidirectional traffic upstream
from the hosts toward the promiscuous ports and the Layer 3 gateway. You can configure one isolated
VLAN in a primary VLAN. In addition, each isolated VLAN can have several isolated ports, and the
traffic from each isolated port also remains completely separate.
• Community VLAN—A community VLAN is a secondary VLAN that carries upstream traffic from the
community ports to the promiscuous port gateways and to other host ports in the same community. You
can configure multiple community VLANs in a private VLAN domain. The ports within one community
can communicate, but these ports cannot communicate with ports in any other community or isolated
VLAN in the private VLAN.
This figure shows the Layer 2 traffic flows within a primary, or private VLAN, along with the types of VLANs
and types of ports.
Cisco Nexus 9000 Series NX-OS Layer 2 Switching Configuration Guide, Release 7.x
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Private VLAN isolated trunk ports carry traffic for normal VLANs as well as for
secondary private VLANs.
Configuring Private VLANs Using NX-OS