Configuring Link Aggregation And Lacp; Overview; Basic Concepts Of Link Aggregation - HP 1910 User Manual

Configuring link aggregation and LACP

Overview

Link aggregation aggregates multiple physical Ethernet ports into one logical link, also called an
aggregation group.
It allows you to increase bandwidth by distributing traffic across the member ports in the aggregation
group. In addition, it provides reliable connectivity because these member ports can dynamically back
up each other.

Basic concepts of link aggregation

Aggregation group, member port, and aggregate interface
Link aggregation is implemented through link aggregation groups. An aggregation group is a group of
Ethernet interfaces combined together, which are called "member ports" of the aggregation group. For
each aggregation group, a logical interface, called an "aggregate interface", is created.
States of the member ports in an aggregation group
A member port in an aggregation group can be in one of the following states:
Selected—A Selected port can forward user traffic.
•
• Unselected—An Unselected port cannot forward user traffic.
The rate of an aggregate interface is the sum of the selected member ports' rates. The duplex mode of an
aggregate interface is consistent with that of the selected member ports. All selected member ports use
the same duplex mode.
For how the state of a member port is determined, see
aggregation
LACP protocol
The Link Aggregation Control Protocol (LACP) is defined in IEEE 802.3ad. It uses link aggregation control
protocol data units (LACPDUs) for information exchange between LACP-enabled devices.
LACP is automatically enabled on interfaces in a dynamic aggregation group. For information about
dynamic aggregation groups, see
LACPDUs to notify the remote system (the partner) of its system LACP priority, system MAC address, LACP
port priority, port number, and operational key. Upon receiving an LACPDU, the partner compares the
received information with the information received on other interfaces to determine the interfaces that
can operate as Selected interfaces. This allows the two systems to reach an agreement on which link
aggregation member ports should be placed in Selected state.
Operational key
When aggregating ports, link aggregation control automatically assigns each port an operational key
based on port attributes, including the port rate, duplex mode and link state configuration.
In an aggregation group, all Selected ports are assigned the same operational key.
mode."
"Dynamic aggregation
170
"Static aggregation mode" and
mode." An LACP-enabled interface sends
"Dynamic