Supported Platforms
Related Documentation
- EX Series
- Understanding Private VLANs on EX Series Switches
- Example: Configuring a Private VLAN on a Single EX Series Switch
- Example: Configuring a Private VLAN Spanning Multiple EX Series Switches
- Creating a Private VLAN on a Single EX Series Switch (CLI Procedure)
- Creating a Private VLAN Spanning Multiple EX Series Switches (CLI Procedure)
- QFabric System, QFX Series standalone switches
- Understanding Private VLANs
- Creating a Private VLAN on a Single Switch
- Creating a Private VLAN Spanning Multiple Switches
- Example: Configuring a Private VLAN on a Single Switch
- Example: Configuring a Private VLAN Spanning Multiple Switches
Understanding PVLAN Traffic Flows Across Multiple Switches
This topic illustrates and explains three different traffic flows on a sample multiswitch network configured with a private VLAN (PVLAN). PVLANs restrict traffic flows through their member switch ports (which are called “private ports”) so that they communicate only with a specific uplink trunk port or with specified ports within the same VLAN.
This topic describes:
Community VLAN Sending Untagged Traffic
In this scenario, a VLAN in Community-1 of Switch 1 at interface ge-0/0/0 sends untagged traffic. The arrows in Figure 1 represent this traffic flow.
Figure 1: Community VLAN Sends Untagged Traffic

In this scenario, the following activity takes place on Switch 1:
- Community-1 VLAN on interface ge-0/0/0: Learning
- pvlan100 on interface ge-0/0/0: Replication
- Community-1 VLAN on interface ge-0/0/12: Receives traffic
- PVLAN trunk port: Traffic exits from ge-1/0/2 and from ae0 with tag 10
- Community-2: Interface receives no traffic
- Isolated VLANs: Interfaces receive no traffic
In this scenario, this activity takes place on Switch 3:
- Community-1 VLAN on interface ge-0/0/23 (PVLAN trunk): Learning
- pvlan100 on interface ge-0/0/23: Replication
- Community-1 VLAN on interface ge-0/0/9 and ge-0/0/16: Receives traffic
- Promiscuous trunk port: Traffic exits from ge-0/0/0 with tag 100
- Community-2: Interface receives no traffic
- Isolated VLANs: Interfaces receive no traffic
Isolated VLAN Sending Untagged Traffic
In this scenario, isolated VLAN1 on Switch 1 at interface ge-1/0/0 sends untagged traffic. The arrows in Figure 2 represent this traffic flow.
Figure 2: Isolated VLAN Sends Untagged Traffic

In this scenario, the following activity takes place on Switch 1:
- Isolated VLAN1 on interface ge-1/0/0: Learning
- pvlan100 on interface ge-1/0/0: Replication
- Traffic exits from pvlan-trunk ge-1/0/2 and ae0 with tag 50
- Community-1 and Community-2: Interfaces receive no traffic
- Isolated VLANs: Interfaces receive no traffic
In this scenario, this activity takes place on Switch 3:
- VLAN on interface ge-0/0/23 (PVLAN trunk port): Learning
- pvlan100 on interface ge0/0/23: Replication
- Promiscuous trunk port: Traffic exits from ge-0/0/0 with tag 100
- Community-1 and Community-2: Interfaces receive no traffic
- Isolated VLANs: Receive no traffic
PVLAN Tagged Traffic Sent on a Promiscuous Port
In this scenario, PVLAN tagged traffic is sent on a promiscuous port. The arrows in Figure 3 represent this traffic flow.
Figure 3: PVLAN Tagged Traffic Sent on a Promiscuous Port

In this scenario, the following activity takes place on Switch 1:
- pvlan100 VLAN on interface ae0 (PVLAN trunk): Learning
- Community-1, Community-2, and all isolated VLANs on interface ae0: Replication
- VLAN on interface ae0: Replication
- Traffic exits from pvlan-trunk ge-1/0/2 with tag 100
- Community-1 and Community-2: Interfaces receive traffic
- Isolated VLANs: Receive traffic
In this scenario, this activity takes place on Switch 3:
- pvlan100 on interface ge-0/0/0: Learning
- Community-1, Community-2 and all isolated VLANs on interface ge-0/0/0: Replication
- VLAN on interface ge-0/0/0: Replication
- Community-1 and Community-2: Interfaces receive traffic
- Isolated VLANs: Receive traffic
Related Documentation
- EX Series
- Understanding Private VLANs on EX Series Switches
- Example: Configuring a Private VLAN on a Single EX Series Switch
- Example: Configuring a Private VLAN Spanning Multiple EX Series Switches
- Creating a Private VLAN on a Single EX Series Switch (CLI Procedure)
- Creating a Private VLAN Spanning Multiple EX Series Switches (CLI Procedure)
- QFabric System, QFX Series standalone switches
- Understanding Private VLANs
- Creating a Private VLAN on a Single Switch
- Creating a Private VLAN Spanning Multiple Switches
- Example: Configuring a Private VLAN on a Single Switch
- Example: Configuring a Private VLAN Spanning Multiple Switches
Published: 2014-04-23
Supported Platforms
Related Documentation
- EX Series
- Understanding Private VLANs on EX Series Switches
- Example: Configuring a Private VLAN on a Single EX Series Switch
- Example: Configuring a Private VLAN Spanning Multiple EX Series Switches
- Creating a Private VLAN on a Single EX Series Switch (CLI Procedure)
- Creating a Private VLAN Spanning Multiple EX Series Switches (CLI Procedure)
- QFabric System, QFX Series standalone switches
- Understanding Private VLANs
- Creating a Private VLAN on a Single Switch
- Creating a Private VLAN Spanning Multiple Switches
- Example: Configuring a Private VLAN on a Single Switch
- Example: Configuring a Private VLAN Spanning Multiple Switches