Unique Identifiers Assignment for Ethernet Segment LAGs

The ESI is structured as follows:

• Type (1 byte): Specifies the format of the ESI Value.
• Value (9 bytes): Varies based on the ESI Type.

The following ESI types are supported:

• Type 0 (T=0x01): Indicates an arbitrary 9-byte ESI value, which is manually configured and managed by the operator.
• Type 1 T=0x00: Auto-generated using Link Aggregation Control Protocol (LACP) parameters:
  • CE LACP System MAC address (6 bytes): Encoded in the high-order 6 bytes of the ESI Value field.
  • CE LACP Port Key (2 bytes): Encoded in the 2 bytes next to the System MAC address.
  • Remaining byte set to 0x00
• Type 3 T=0x03: Based on a MAC address and a local discriminator value:
  • System MAC address (6 bytes): Must be the same across all multihomed PEs.
  • Local Discriminator value (3 bytes): Configured to form the complete ESI value.