Flexible Ethernet Services Encapsulation

 

Flexible Ethernet services is a type of encapsulation that enables a physical interface to support different types of Ethernet encapsulations at the logical interface level. Flexible Ethernet services encapsulation can be configured to support the service provided and the enterprise style configuration. The below topics discuss the overview of flexible Ethernet services encapsulation, and its configuration details.

Understanding Flexible Ethernet Services Encapsulation on Switches

Junos OS supports two different styles of configuration for switch interfaces: the service provider style and the enterprise style. The service provider style requires more configuration but provides greater flexibility. The enterprise style is easier to configure but offers less functionality. Each configuration style requires a different Ethernet encapsulation type. You can configure a physical interface to support both styles of configuration using flexible Ethernet services.

Note

On EX4300, QFX5100 (running Junos OS 16.1R5 or earlier), and QFX5200, the service provider style and enterprise style interface configurations are handled differently within Junos OS. If the service provider style and enterprise style interface configurations are mixed, the egress VLAN translation within the hardware can be incorrectly programmed leading to forwarding issues across the configured ports. Use the service provider style configuration in a Q-in-Q scenario. For all other scenarios, use the enterprise style configuration.

Flexible Ethernet services is a type of encapsulation that enables a physical interface to support different types of Ethernet encapsulations at the logical interface level. Defining multiple per-unit Ethernet encapsulations makes it easier to customize Ethernet-based services to multiple hosts connected to the same physical interface.

Service Provider Style

The service provider style of configuration allows for customization of Ethernet-based services at the logical interface level. Service providers typically have multiple customers connected to the same physical interface. Using the service provider style, you can configure multiple logical interfaces on the physical interface, and associate each unit with a different VLAN. This provides the flexibility to configure different services for each customer, but also requires more configuration, because each feature must be explicitly configured on the logical interface.

When configuring a physical interface to support only the service provider style, the physical interface must be encapsulated with the extended-vlan-bridge option to support bridging features. VLAN tagging must also be configured on the physical interface so that it can operate in trunk mode and transmit Ethernet frames with VLAN tags for multiple VLANs. Each logical interface is bound to a unique VLAN ID.

Enterprise Style

The enterprise style of configuration is designed to provide basic bridging functionality for consumers of Ethernet-based services. The isolation of services for different customers on a single port is not required, because each port is typically connected to a host or is providing a trunk to another switch.

With the enterprise style of configuration, logical interfaces are placed into Layer 2 mode by specifying ethernet-switching as the interface family. Without using flexible Ethernet services, ethernet-switching can only be configured on a single logical unit, unit 0. You cannot bind a VLAN ID to unit 0, because these interfaces operate either in trunk mode, which supports traffic with various VLAN tags, or in access mode, which supports untagged traffic.

Flexible Ethernet Services

The flexible Ethernet services encapsulation type enables a physical interface to support both styles of configuration. To support the service provider style, flexible Ethernet services allows for encapsulations to be configured at the logical interface level instead of the physical interface. To support the enterprise style, flexible Ethernet services allows the ethernet-switching family to be configured on any logical interface unit number instead of only unit 0.

For example, the configuration below shows three logical interfaces configured on a physical interface, xe-0/0/51, that is encapsulated for flexible Ethernet services. Unit 100 and unit 200 are configured in the service provider style and unit 300 is configured in the enterprise style. The encapsulation type of vlan-bridge is used to enable bridging on unit 100 and unit 200, and family ethernet-switching enables bridging on unit 300.

Note

It is not required that the unit number and VLAN ID match, but it is considered a best practice.

Note

On QFX5100 switches, you can combine encapsulations on the same physical interface for vlan-bridge and family ethernet switching. Starting with Junos OS Release 16.1R6, you can also combine encapsulations on the same physical interface for family inet and family ethernet-switching.

Configuring Flexible Ethernet Services Encapsulation to Support the Service Provider and Enterprise Styles of Configuration

Flexible Ethernet services is a type of encapsulation that enables a physical interface to specify Ethernet encapsulations at the logical interface level. Each logical interface can have a different Ethernet encapsulation. Defining multiple per-unit Ethernet encapsulations makes it easier to customize Ethernet-based services to multiple hosts connected to the same physical interface.

An Ethernet interface that is not encapsulated with flexible Ethernet services and is operating in Layer 2 mode is limited to a single logical interface unit (0). Bridging is enabled on the interface by configuring ethernet-switching as the interface family on unit 0. The ethernet-switching family can be configured only on logical interface unit 0, and no other logical units can be defined on that interface.

Some switching features, however, cannot be configured on logical interface unit 0. Features such as Q-in-Q tunneling require the logical interface to transmit VLAN-tagged frames. To enable a logical interface to receive and forward Ethernet frames tagged with a matching VLAN ID, you must bind the logical interface to that VLAN. These features must be configured on a logical interface unit other than 0, because you cannot bind a VLAN ID to unit 0.

When you encapsulate an interface by using flexible Ethernet services, you can configure a logical interface unit other than 0 with family ethernet-switching. You can also configure other logical interfaces on that same interface with different types of Ethernet encapsulations. This enables logical interfaces that are bound to a VLAN ID to coexist with logical interfaces configured with family ethernet-switching.

For example, if you configure PVLAN on the same physical interface on which you are configuring Q-in-Q tunneling, you can use flexible ethernet services to support the enterprise style of configuration for PVLAN, using family ethernet-switching, along with vlan-bridge encapsulation for Q-in-Q tunneling.

To configure the interface to support both the service provider and enterprise styles of configuration:

  1. Enable flexible Ethernet services encapsulation on the interface. The flexible-ethernet-services statement allows configuration of both service-provider-style logical interfaces and enterprise-style logical interfaces:
    [edit interfaces interface-name]
    user@switch# set encapsulation flexible-ethernet-services
  2. Enable the interface to transmit packets with 802.1Q VLAN single-tagged and dual-tagged frames:
    [edit interfaces interface-name]
    user@switch# set flexible-vlan-tagging
  3. Configure a logical interface (unit) on the interface:
    [edit interfaces interface-name]
    user@switch# set unit unit-number
    Note

    Do not use logical interface unit 0. You must later bind a VLAN tag ID to the unit you specify in this step, and you cannot bind a VLAN tag ID to unit 0. It is a best practice to match the unit number to the VLAN ID to which the interface is bound.

  4. Encapsulate the logical interface for service provider style bridging configuration—for example, use vlan-bridge encapsulation on an interface to be used for Q-in-Q tunneling. (If you were configuring the interface only for Q-in-Q tunneling, you would use encapsulation extended-vlan-bridge on the physical interface.)
    [edit interfaces interface-name]
    user@switch# set unit unit-number encapsulation vlan-bridge
  5. Bind the logical interface from the preceding step to a VLAN ID:
    [edit interfaces interface-name]
    user@switch# set unit unit-number vlan-id vlan-id
  6. Configure another logical interface. (If you were configuring just PVLAN, we would recommend that you configure a single logical interface for all PVLAN domains on an interface.)
    [edit interfaces interface-name]
    user@switch# set unit unit-number
  7. Enable the logical interface in the preceding step for enterprise style bridging configuration:
    [edit interfaces interface-name]
    user@switch# set unit unit-number family ethernet-switching
  8. Assign VLAN membership to the logical interface:
    [edit interfaces interface-name]
    user@switch# set unit unit-number family ethernet-switching vlan members vlan-id
  9. Configure the interface as a trunk interface to transmit frames with 802.1Q VLAN tags:
    [edit interfaces interface-name]
    user@switch# set unit unit-number family ethernet-switching interface-mode trunk
Note

For EX4300 device, the service provider style configuration (encapsulation extended-vlan-bridge) is recommended only for QinQ scenarios. For other scenarios, use the enterprise style configuration.

Release History Table
Release
Description
Starting with Junos OS Release 16.1R6, you can also combine encapsulations on the same physical interface for family inet and family ethernet-switching.