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Service Chaining on NFX150 Devices

Understanding Service Chaining

In many network environments, it is common for traffic to flow through several network services on the way to its destination. These services—firewalls, Network Address Translators (NAT), load balancers, and so on—are generally spread across multiple network elements. Each device is a separate piece of hardware, providing a different service, and requiring separate operation and management. This method of linking together multiple network functions could be thought of as physical service chaining.

A more efficient model for service chaining is to virtualize and consolidate network functions onto a single device.

Virtualized service chaining is supported on NFX150 devices starting with Junos OS Release 18.1. Virtual network functions (VNFs) can be installed and linked together to provide L2, L3, and L4-L7 services for traffic flowing through the device.

Configuring Service Chaining Using VLANs


Ensure that connectivity to the host is not lost during the configuration process.

To configure service chaining:

  1. Create a VLAN. Use one of the following commands:
    • Create a VLAN without a VLAN ID. You can add only access ports to this VLAN:

    • Create a VLAN with a VLAN ID:

    • Create a VLAN using a list of VLAN IDs:

  2. Attach an interface on the VNF to the VLAN:
  3. Attach a native VLAN ID to the VNF interface:

Configuring Service Chaining Using DHCP Services on VLANs

Using DHCP services, you need not manually configure the IP addresses on the VNF interfaces to achieve service-chaining. Enable DHCP clients on the glue bridge interfaces within the VNF for an IP address to be assigned from the DHCP pool.

To configure service chaining:

  1. Create a VLAN with a VLAN ID none.

    To use the DHCP pooling feature, the VLAN ID must be set to none.

  2. Specify the IP address pool to be used:
  3. Attach an interface from FPC1 to the VLAN:
  4. Configure an IP address on the interface and enable dhcp-server on it.
  5. Attach an interface on the VNF to the VLAN to complete the service chain:
  6. Enable the DHCP client on the VNF.

To check the assigned IP address, use the show system visibility vnf command.