Link Aggregation

Link Aggregation Introduction

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.

Network Diagram

Figure 1-1 Network diagram for link aggregation configuration

Networking and Configuration Requirements

Switch A aggregates ports GigabitEthernet 1/0/1 through GigabitEthernet 1/0/3 to form one link connected to Switch B and performs load sharing among these ports.

Configuration Example

1)        Manual aggregation mode:

#

 link-aggregation group 1 mode manual

#

interface GigabitEthernet1/0/1

 port link-aggregation group 1

#

interface GigabitEthernet1/0/2

 port link-aggregation group 1

#

interface GigabitEthernet1/0/3

 port link-aggregation group 1

#

2)        Static LACP aggregation mode:

#

 link-aggregation group 1 mode static

interface GigabitEthernet1/0/1

 port link-aggregation group 1

#

interface GigabitEthernet1/0/2

 port link-aggregation group 1

#

interface GigabitEthernet1/0/3

 port link-aggregation group 1

#

Link aggregation support of release 6300 of the 7500 series Ethernet switches differs slightly. The aggregation group configuration procedure is as follows:

l              Static aggregation mode

#

interface Bridge-Aggregation1

#

interface GigabitEthernet1/0/1

 port link-aggregation group 1

#

interface GigabitEthernet1/0/2

 port link-aggregation group 1

#

interface GigabitEthernet1/0/3

 port link-aggregation group 1

#

l              Dynamic aggregation mode

#

interface Bridge-Aggregation1

 link-aggregation mode dynamic

#

interface GigabitEthernet1/0/1

 port link-aggregation group 1

#

interface GigabitEthernet1/0/2

 port link-aggregation group 1

#

interface GigabitEthernet1/0/3

 port link-aggregation group 1

#

Configuration Guidelines

l          Compatibility problems may occur when devices are connected to one another through static aggregation in different software, since the implementation approach of static aggregation varies with software. You can use the display version command to view the software version information.

l          An RRPP-configured port, a static MAC address or blackhole MAC address-configured port, a voice VLAN-enabled port, and an 802.1x-enabled port cannot be added to an aggregation group.