Chapter 1 Link Aggregation Configuration; Overview; Introduction To Link Aggregation; Introduction To Lacp - H3C S3100-52P Operation Manual

Operation Manual – Link Aggregation
H3C S3100-52P Ethernet Switch

Chapter 1 Link Aggregation Configuration

1.1 Overview

1.1.1 Introduction to Link Aggregation

Link aggregation means aggregating several ports together to form an aggregation
group, so as to implement outgoing/incoming load sharing among the member ports in
the group and to enhance the connection reliability.
Depending on different aggregation modes, link aggregation falls into three types:
manual, static LACP, and dynamic LACP aggregations. Depending on whether or not
load sharing is implemented, aggregation groups can be load-sharing or
non-load-sharing aggregation groups.
For the member ports in an aggregation group, their basic configuration must be the
same. The basic configuration includes STP, QoS, VLAN, port attributes and other
associated settings.
STP configuration, including STP status (enabled or disabled), link attribute
(point-to-point or not), STP priority, path cost, standard packet format, maximum
packet transmission speed, loop prevention status, root protection status, edge
port or not.
QoS configuration, including traffic limit, priority remarking, default 802.1p priority,
bandwidth assurance, congestion avoidance, traffic redirection, traffic statistics,
and so on.
VLAN configuration, including permitted VLANs, and default VLAN ID.
Port attribute configuration, including port rate, duplex mode, and link type (Trunk,
Hybrid or Access). The ports for a manual or static aggregation group must have
the same link type, and the ports for a dynamic aggregation group must have the
same rate, duplex mode and link type.

1.1.2 Introduction to LACP

The purpose of link aggregation control protocol (LACP) is to implement dynamic link
aggregation and deaggregation. This protocol is based on IEEE802.3ad and uses
LACPDUs (link aggregation control protocol data unit) to interact with its peer.
After LACP is enabled on a port, LACP notifies the following information of the port to its
peer by sending LACPDUs: priority and MAC address of this system, priority, number
and operation key of the port. Upon receiving the information, the peer compares the
information with the information of other ports on the peer device to determine the ports
that can be aggregated. In this way, the two parties can reach an agreement in
adding/removing the port to/from a dynamic aggregation group.
Chapter 1 Link Aggregation Configuration
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