Ethernet Segment Configuration and Management

Ethernet Segments (ES) local to a device are configured through the command line interface (CLI) and stored in the ES Manager (ES-Mgr) module. The ES-Mgr handles multihoming configuration information, including an ES identified by a unique ID, the ES Type, associated Link Aggregation Group (LAG) ID, and the redundancy mode.

The following configurations are supported:

  • Redundancy Modes: All-Active and Single-Active. In All-Active mode, all member links of the LAG are operational. In Single-Active mode, only one member link is operational. Refer to the Ethernet Segment Redundancy Mode section for more information.
  • LAG Types: Static and Dynamic.
  • ES Types: Type-0, Type-1, and Type-3. All three types support Dynamic LAG. Static LAG supports only Type-0 and Type-3. Refer to the Unique Identifiers Assignment for Ethernet Segment LAGs section for more information.

The ES-Mgr performs the following activities:

  • For Dynamic LAGs:
    • For Type-1 Ethernet Segment Identifiers (ESIs), the ES-Mgr exchanges Media Access Control (MAC) address and Port Key values with the Customer Edge (CE) device via Link Aggregation Control Protocol (LACP). It constructs the ESI by combining the ES Type with the received MAC address and Port Key values. It stores and shares the constructed ESI with Border Gateway Protocol (BGP) once the dynamic LAG is up.
    • For Type-0 or Type-3 ESIs, constructs the ESI as described in the Unique Identifiers Assignment for Ethernet Segment LAGs section.
  • For Static LAGs:
    • Computes the unique 10-byte ESI by combining the local ES Type, MAC address, and local discriminator value.
    • Shares the computed ESI with BGP.
  • Maintains two Finite State Machines (FSMs) to manage multihoming configurations, including the exchange of MAC and Port Key values and ESI construction.
  • Associates each ES-LAG with a physical LAG interface. When the LAG interface joins a Virtual Local Area Network (VLAN), the ES becomes a member of the corresponding Ethernet Virtual Instance (EVI).
  • Constructs and sends (ES, EVI) mappings to BGP based on the LAG interface's VLAN membership.
  • Keeps VLAN mappings without EVI outside the EVPN domain.
  • Sends all local ES information, including ES parameters, operational state, and (ES, EVI) mappings, to BGP and notifies BGP of any changes.
Parent topic: BGP EVPN Multihoming