Reference Guide

Link Aggregation Control Protocol (LACP) | 541

Link Aggregation Control Protocol (LACP)

Link Aggregation Control Protocol (LACP) is supported on platforms: e c s

The major sections in the chapter are:

• Introduction to Dynamic LAGs and LACP

• LACP Configuration Tasks

• Shared LAG State Tracking

• Configure LACP as Hitless

• LACP Basic Configuration Example

Introduction to Dynamic LAGs and LACP

A Link Aggregation Group (LAG), referred to as a port channel by FTOS, can provide both

load-sharing and port redundancy across line cards. LAGs can be enabled as static or dynamic.

The benefits and constraints are basically the same, as described in Port Channel Interfaces in the

Interfaces chapter.

The unique benefit of a dynamic LAG is that its ports can toggle between participating in the LAG

or acting as dedicated ports, whereas ports in a static LAG must be specifically removed from the

LAG in order to act alone.

FTOS uses LACP to create dynamic LAGs. LACP provides a standardized means of exchanging

information between two systems (also called Partner Systems) and automatically establishes the

LAG between the systems. LACP permits the exchange of messages on a link to allow their LACP

instances to:

• Reach agreement on the identity of the LAG to which the link belongs.

• Move the link to that LAG.

• Enable the transmission and reception functions in an orderly manner.

The FTOS implementation of LACP is based on the standards specified in the IEEE 802.3:

“Carrier sense multiple access with collision detection (CSMA/CD) access method and physical

layer specifications.”