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Example: Configuring Cross-Connect Using a Custom Bridge on NFX150 Devices

This example shows how to configure cross-connect using a custom bridge on NFX150 devices.


This example uses the following hardware and software components:

  • NFX150 running Junos OS Release 18.1R1


The Cross-connect feature enables traffic switching between any two VNF interfaces. You can bidirectionally switch either all traffic or traffic belonging to a particular VLAN between any two VNF interfaces.


This feature does not support unidirectional traffic flow.

The Cross-connect feature supports the following:

  • Port cross-connect between two VNF interfaces for all network traffic.

  • VLAN-based traffic forwarding between VNF interfaces that support the following functions:

    • Provides an option to switch traffic based on a VLAN ID.

    • Supports network traffic flow from trunk to access port through POP operation.

    • Supports network traffic flow from access to trunk port through PUSH operation.

    • Supports VLAN PUSH, POP, and SWAP operations.


This example uses the topology shown in Figure 1.

Figure 1: Configuring Cross-ConnectConfiguring Cross-Connect


Create VLANs

Step-by-Step Procedure

  1. Configure VLANs for the LAN-side interfaces.

Map the Interfaces

Step-by-Step Procedure

  1. Map the heth-0-0 physical port to the FPC0 interface.

  2. Create the custom bridge.

  3. Map the FPC1 interface ge-1/0/2 to the custom bridge.

Configure the Layer 2 Datapath

Step-by-Step Procedure

  1. Configure the LAN-side front panel ports and add them to the LAN-side VLAN.

  2. Configure the internal-facing interfaces as trunk ports and add them to the LAN-side VLAN. The internal-facing interfaces are typically trunk ports, as they must support traffic from multiple front panel ports and VLANs.

Configure the Layer 3 Datapath

Step-by-Step Procedure

  1. Configure VLAN tagging on ge-1/0/0:

  2. Configure VLAN tagging on ge-1/0/2:

Configure the VNF

Step-by-Step Procedure

  1. Launch the VNF:

  2. Specify the number of CPUs required for the VNF:

  3. Pin a virtual CPU to a physical CPU:

  4. Create a VNF interface on the custom OVS bridge:

  5. Attach a VNF interface to a physical interface by using the SR-IOV virtual function:

  6. Specify the memory allocation for the VNF:

Configure Cross-Connect

Step-by-Step Procedure

  1. Configure cross-connect:

Verifying the Configuration

Verify the Control Plane Configuration


Verify the control plane configuration:


To verify the control plane configuration:

  • Verify that the VLANs and VLAN memberships are correct by using the show vmhost vlans command.

  • Verify that the VNF is operational. View the status of the VNF to ensure that the VNF is up and running.

    The Liveliness output field of the VNF indicates whether the IP address of the VNF is reachable or not reachable from Junos.

    To view more details of the VNF:

Verify the Data Plane Configuration


Verify the data plane configuration.


To verify the data plane configuration:

  • Verify the status of the physical ports.

  • Verify the status of the Layer 2 (ge-0/0/x) and Layer 3 (ge-1/0/x) interfaces.

    For example: