Configuring Ethernet Interfaces

This section describes the options for configuring Ethernet interfaces.

You configure an Ethernet interface based on the requirements for your router configuration and the protocols you plan to route on the interface. Because you can configure an interface in different ways, Ethernet configuration tasks are divided into three primary areas. These areas are further described in separate sections in this chapter.

• Configuring the physical interface—You must perform basic configuration steps for all interfaces. This task begins with selecting an Ethernet interface and setting parameters such as line speed and MTU.

  See Configuring the Physical Interface.

• Configuring VLANs and stacked VLANs (S-VLANs)—After you configure the physical interface, you must decide whether to configure the Ethernet interface with or without VLANs or S-VLANs. VLANs and S-VLANs enable you to multiplex multiple IP interfaces and PPPoE interfaces over a single physical Ethernet port. If you are not configuring with VLANs or S-VLANs, proceed to Unresolved xref.
• Configuring upper-layer protocols—You must determine which upper-layer protocols, such as MPLS, to configure on the interface. This section focuses on non-VLAN configurations. You can configure some upper-layer protocols, such as PPPoE, with or without VLANs. For more information, see JunosE Link Layer Configuration Guide .