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Prerequisites to Onboard Virtual Network Functions on NFX350 Devices


You can onboard and manage Juniper Virtual Network Functions (VNFs) and third-party VNFs on NFX devices through the Junos Control Plane (JCP).


This topic provides general guidelines to qualify VNFs on NFX350 devices. Before onboarding a VNF, you must test the VNF according to your use case scenario.

NFX350 Device Prerequisites to Onboard a VNF

To onboard VNFs on NFX350, the device must be on either Hybrid mode or Compute mode. The number of VNFs that you can onboard on the device depends on the system resources such as CPUs and system memory that are available on the mode that the device is operating. For more information about the performance modes, see NFX350 Overview.

Before you onboard the VNF, check the following NFX350 device capabilities:

  • Check the current performance mode of the device by using the show vmhost mode command. The NFX350 device must be in either Compute or Hybrid mode when you run the show vmhost mode command.

  • Check the available system memory by using the show system visibility memory command.

    Table 1 lists the possible memory availability for VNF usage for the NFX350 models.

    Table 1: Memory Availability for VNF Usage (Junos OS 19.4R1 Release)


    Total System Memory

    Hugepages Availability for VNF Usage


    32 GB

    7 1G hugepages


    64 GB

    23 1G hugepages


    128 GB

    62 1G hugepages

  • Check the available CPUs and its status by using the show system visibility cpu command. Use the show vmhost mode command to check the available CPUs in the current performance mode of the device.

    Table 2 lists the CPUs available for VNF usage for the NFX350 models.

    Table 2: CPUs Available for VNF Usage (Junos OS 19.4R1 Release)


    CPUs Available for VNF Usage

    Throughput Mode

    Hybrid Mode

    Compute Mode














    When you change the performance mode of the device, it is recommended to check the availability of the CPUs for VNFs.


On NFX350 devices, it is recommended to use external SSD for storing VNF images or files.

For more information, see Configuring VNFs on NFX350 Devices.

VNF Prerequisites to Onboard on an NFX350 Device

To onboard a VNF on an NFX350 device, the following VNF properties should be met:


For VNF production deployment, it is recommended to use external hard disk.

  • KVM based hypervisor deployment

  • OVS or Virtio interface drivers

  • raw or qcow2 VNF file types

  • Support of up to a maximum of 8 user interfaces

Following are the optional prerequisites to onboard a VNF:

  • (Optional) SR-IOV

  • (Optional) CD-ROM and USB configuration drives

  • (Optional) Hugepages for memory requirements if VNF wants to access OVS.

Validate the VNFs

To validate and qualify the VNFs, you must ensure the following:

  • The configuration commit succeeds for the VNF.

  • The show virtual-network-functions command output displays the VNF entry.

  • The show system visibility vnf command output displays the VNF properties and interfaces that are configured.

  • The show vmhost network nfv-back-plane command displays all interfaces that are connected to the OVS bridges with the state up/up. The show system visibility network command displays all the VNF interfaces.

  • Connection to the console of the VNF succeeds and VNF boot up or login prompt is displayed.

  • When you are logged into the VNF, use the request virtual-network-function console command for the VNF to display all the interfaces that are configured.

  • The show virtual-network-functions command lists the VNF that are alive when the internal management interface is configured with DHCP client inside the VNF.

  • VNF interfaces on the OVS bridge show tx/rx statistics when the traffic is ingressed or egressed from the VNF.

  • VNF should restart successfully when a restart is initiated from within the VNF or by using the request virtual-network-functions restart vnf-name command.

For sample configuration of third-party VNFs, see Example: Configuring Service Chaining for LAN to WAN Routing through Third-party VNFs on NFX350 Devices.

Sample Output

  • show virtual-network-functions

    root@host> show virtual-network-functions

    The Liveliness is alive when there is a management connectivity to the VNF. The State should be Running to show that the VNF is up.

  • show system visibility vnf

    root@host> show system visibility vnf
  • request virtual-network-functions vsrx console

    root@host> request virtual-network-functions vsrx console
  • show system visibility memory

    root@host> show system visibility memory

    In the output message, check Free and Configured fields under Virtual Memory and Huge Pages sections for the memory availability.

  • show vmhost mode

    root@host> show vmhost mode

    In the output message, check the Current Mode field under the Mode section for the current performance mode of the device. Check the CPUs available for VNFs field under the CPU Allocations section for the CPU availability.