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Example: Configuring Service Chaining Using VLANs on NFX350 Devices

This example shows how to configure service chaining using VLANs on the host bridge.

Requirements

This example uses an NFX350 device running Junos OS Release 19.4R1.

Before you configure service chaining, ensure that you have installed and instantiated the relevant virtual network functions (VNFs), assigned the corresponding interfaces, and configured the resources.

Overview

Service chaining on a device enables multiple services or VNFs on the traffic that flows through the device. This example explains how to configure the various layers of the device to enable traffic to enter the device, flow through two service VNFs, and exit the device.

Topology

This example uses a single NFX350 device running Junos OS, as shown in Figure 1.

Figure 1: Configuring Service Chaining Using VLANsConfiguring Service Chaining Using VLANs

This example is configured using the Junos Control Plane (JCP). The key configuration elements include:

  • Front panel ports

  • Internal-facing ports

  • VNF interfaces, which use the naming format eth# (where # ranges from 0 through 9)

  • VLANs to provide bridging between the static interfaces (sxe) and VNF interfaces

Configuration

Configuring the JCP Interfaces

Step-by-Step Procedure

To configure the interfaces:

  1. Log in to the CLI.

  2. Map the Layer 3 interface to the Open vSwitch (OVS).

  3. Configure a VLAN for the LAN-side interfaces.

  4. Configure the LAN-side front panel port and add it to the LAN-side VLAN.

    The LAN-side port is typically an access port, but can be a trunk port if required.

  5. Configure the LAN-side internal-facing interface as a trunk port and add it 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.

  6. Configure the WAN-side internal-facing interface as a trunk port and add it to the WAN-side VLAN.

  7. Configure the WAN-side front panel port and add it to the WAN-side VLAN.

  8. Configure a VLAN for the WAN-side interface.

  9. Configure VLAN tagging on the WAN-side external facing interface and assign an IP address.

  10. Configure the WAN-side internal facing interface as a VLAN-tagged interface and assign an IP address.

  11. Commit the configuration.

Results

From configuration mode, check the results of your configuration by entering the following show commands:

Configuring the VNF Interfaces and Creating the Service Chain

Step-by-Step Procedure

Configure the VNF interfaces.

  1. Configure the vmhost instance with the LAN, WAN, or the glue VLANs to be used for service chaining:

  2. Instantiate the VNF (vnf-name1) with one virtio interface mapped to the VLAN vlan1 and the other virtio interface mapped to the VLAN glue-vlan1.

  3. Instantiate the second VNF (vnf-name2) with one interface mapped to the VLAN vlan2 and the second interface mapped to the same glue-vlan1.

  4. Configure the IP addresses and static routes for each interface of the VNFs as shown in Figure 1.