Example: Configuring a Private VLAN on a Single EX Series Switch

For security reasons, it is often useful to restrict the flow of broadcast and unknown unicast traffic and to even limit the communication between known hosts. The private VLAN (PVLAN) feature on EX Series switches allows an administrator to split a broadcast domain into multiple isolated broadcast subdomains, essentially putting a VLAN inside a VLAN.

This example describes how to create a PVLAN on a single EX Series switch:

Note: Configuring a voice over IP (VoIP) VLAN on PVLAN interfaces is not supported.

Requirements

This example uses the following hardware and software components:

• One EX Series switch
• Junos OS Release 9.3 or later for EX Series switches

Before you begin configuring a PVLAN, make sure you have created and configured the necessary VLANs. See Configuring VLANs for EX Series Switches (CLI Procedure) or Configuring VLANs for EX Series Switches (J-Web Procedure).

Overview and Topology

In a large office with multiple buildings and VLANs, you might need to isolate some workgroups or other endpoints for security reasons or to partition the broadcast domain. This configuration example shows a simple topology to illustrate how to create a PVLAN with one primary VLAN and two community VLANs, one for HR and one for finance, as well as two isolated ports; one for the mail server and the other for the backup server.

Table 1 lists the settings for the example topology.

Figure 1 shows the topology for this example.

Figure 1: PVLAN Topology on a Single Switch

Configuration

To configure a PVLAN, perform these tasks:

CLI Quick Configuration

To quickly create and configure a PVLAN, copy the following commands and paste them into the switch terminal window:

Step-by-Step Procedure

To configure the PVLAN:

1. Set the VLAN ID for the primary VLAN:
   
   

   [edit vlans]
user@switch# set pvlan vlan-id 1000
2. Set the interfaces and port modes:
   
   

   [edit interfaces]
user@switch# set ge-0/0/0 unit 0 family ethernet-switching port-mode trunk

   
   

   user@switch# set ge-0/0/0 unit 0 family ethernet-switching vlan members pvlan

   
   

   user@switch# set ge-1/0/0 unit 0 family ethernet-switching port-mode trunk

   
   

   user@switch# set ge-1/0/0 unit 0 family ethernet-switching vlan members pvlan

   
   

   user@switch# set ge-0/0/11 unit 0 family ethernet-switching port-mode access

   
   

   user@switch# set ge-0/0/12 unit 0 family ethernet-switching port-mode access

   
   

   user@switch# set ge-0/0/13 unit 0 family ethernet-switching port-mode access

   
   

   user@switch# set ge-0/0/14 unit 0 family ethernet-switching port-mode access

   
   

   user@switch# set ge-0/0/15 unit 0 family ethernet-switching port-mode access

   
   

   user@switch# set ge-0/0/16 unit 0 family ethernet-switching port-mode access
3. Set the primary VLAN to have no local switching:

   Note: The primary VLAN must be a tagged VLAN.

   
   

   [edit vlans]
user@switch# set pvlan no-local-switching
4. Add the trunk interfaces to the primary VLAN:
   
   

   [edit vlans]
user@switch# set pvlan interface ge-0/0/0.0

   
   

   user@switch# set pvlan interface ge-1/0/0.0
5. For each secondary VLAN, configure access interfaces:

   Note: We recommend that the secondary VLANs be untagged VLANs. It does not impair functioning if you tag the secondary VLANS. However, the tags are not used when a secondary VLAN is configured on a single switch.

   
   

   [edit vlans]
user@switch# set hr-comm interface ge-0/0/11.0

   
   

   user@switch# set hr-comm interface ge-0/0/12.0

   
   
   

   user@switch# set finance-comm interface ge-0/0/13.0

   
   

   user@switch# set finance-comm interface ge-0/0/14.0
6. For each community VLAN, set the primary VLAN:
   
   

   [edit vlans]
user@switch# set hr-comm primary-vlan pvlan

   
   

   user@switch# set finance-comm primary-vlan pvlan
7. Add each isolated interface to the primary VLAN:
   
   

   [edit vlans]
user@switch# set pvlan interface ge-0/0/15.0

   
   

   user@switch# set pvlan interface ge-0/0/16.0

Results

Check the results of the configuration:

Verification

To confirm that the configuration is working properly, perform these tasks:

• Verifying That the Private VLAN and Secondary VLANs Were Created

Verifying That the Private VLAN and Secondary VLANs Were Created

Purpose

Verify that the primary VLAN and secondary VLANs were properly created on the switch.

Action

Use the show vlans command:

VLAN: pvlan, Created at: Tue Sep 16 17:59:47 2008
802.1Q Tag: 1000, Internal index: 18, Admin State: Enabled, Origin: Static
Private VLAN Mode: Primary
Protocol: Port Mode
Number of interfaces: Tagged 2 (Active = 0), Untagged  6 (Active = 0)
      ge-0/0/0.0, tagged, trunk
      ge-0/0/11.0, untagged, access
      ge-0/0/12.0, untagged, access
      ge-0/0/13.0, untagged, access
      ge-0/0/14.0, untagged, access
      ge-0/0/15.0, untagged, access
      ge-0/0/16.0, untagged, access
      ge-1/0/0.0, tagged, trunk
Secondary VLANs: Isolated 2, Community  2
  Isolated VLANs :
      __pvlan_pvlan_ge-0/0/15.0__
      __pvlan_pvlan_ge-0/0/16.0__
  Community VLANs :
      finance-comm
      hr-comm

VLAN: hr-comm, Created at: Tue Sep 16 17:59:47 2008
Internal index: 22, Admin State: Enabled, Origin: Static
Private VLAN Mode: Community, Primary VLAN: pvlan
Protocol: Port Mode
Number of interfaces: Tagged 2 (Active = 0), Untagged  2 (Active = 0)
      ge-0/0/0.0, tagged, trunk
      ge-0/0/11.0, untagged, access
      ge-0/0/12.0, untagged, access
      ge-1/0/0.0, tagged, trunk

VLAN: finance-comm, Created at: Tue Sep 16 17:59:47 2008
Internal index: 21, Admin State: Enabled, Origin: Static
Private VLAN Mode: Community, Primary VLAN: pvlan
Protocol: Port Mode
Number of interfaces: Tagged 2 (Active = 0), Untagged  2 (Active = 0)
      ge-0/0/0.0, tagged, trunk
      ge-0/0/13.0, untagged, access
      ge-0/0/14.0, untagged, access
      ge-1/0/0.0, tagged, trunk

VLAN: __pvlan_pvlan_ge-0/0/15.0__, Created at: Tue Sep 16 17:59:47 2008
Internal index: 19, Admin State: Enabled, Origin: Static
Private VLAN Mode: Isolated, Primary VLAN: pvlan
Protocol: Port Mode
Number of interfaces: Tagged 2 (Active = 0), Untagged  1 (Active = 0)
      ge-0/0/0.0, tagged, trunk
      ge-0/0/15.0, untagged, access
      ge-1/0/0.0, tagged, trunk

VLAN: __pvlan_pvlan_ge-0/0/16.0__, Created at: Tue Sep 16 17:59:47 2008
Internal index: 20, Admin State: Enabled, Origin: Static
Private VLAN Mode: Isolated, Primary VLAN: pvlan
Protocol: Port Mode
Number of interfaces: Tagged 2 (Active = 0), Untagged  1 (Active = 0)
      ge-0/0/0.0, tagged, trunk
      ge-0/0/16.0, untagged, access
      ge-1/0/0.0, tagged, trunk

Meaning

The output shows that the primary VLAN was created and identifies the interfaces and secondary VLANs associated with it.