Ethernet Link Aggregation

Aggregates multiple physical links into one logical link to increase the link bandwidth.

Each member port has two aggregation states:

1)    Selected:-  can forward user traffic. 

2)    Unselected:-  cannot forward user traffic.

Link aggregation modes:

Static:

Pros: It does not use LACP. Aggregation is stable. The aggregation state of the member

ports is not affected by their peers.

Cons: The member ports cannot change their aggregation state in consistent with their peers. The administrator needs to manually maintain link aggregations.

Dynamic: 

Pros: It uses LACP. The administrator does not need to maintain link aggregations. The peer systems maintain the aggregation state of the member ports automatically.

Cons: The aggregation state of member ports is easily affected by the network environment, which makes dynamic aggregation instable. 

STATIC

[SW1] interface bridge-aggregation 1

[SW1-Bridge-Aggregation1] quit

Assign ports GigabitEthernet 1/0/1 through GigabitEthernet 1/0/3 to link aggregation group 1

[SW1] interface gigabitethernet 1/0/1

[SW1-gigabitethernet1/0/1] port link-aggregation group 1

[SW1-gigabitethernet1/0/1] quit

[SW1] interface gigabitethernet 1/0/2

[SW1-gigabitethernet1/0/2] port link-aggregation group 1

[SW1-gigabitethernet1/0/2] quit

[SW1] interface gigabitethernet 1/0/3

[SW1-gigabitethernet1/0/3] port link-aggregation group 1

[SW1-gigabitethernet1/0/3] quit

Configure SW2 as we configure SW1

DYNAMIC

[SW1] interface bridge-aggregation 1

[SW1-Bridge-Aggregation1] link-aggregation mode dynamic

[SW1-Bridge-Aggregation1] quit

Assign ports GigabitEthernet 1/0/1 through GigabitEthernet 1/0/3 to link aggregation group 1

[SW1] interface gigabitethernet 1/0/1

[SW1-gigabitethernet1/0/1] port link-aggregation group 1

[SW1-gigabitethernet1/0/1] quit

[SW1] interface gigabitethernet 1/0/2

[SW1-gigabitethernet1/0/2] port link-aggregation group 1

[SW1-gigabitethernet1/0/2] quit

[SW1] interface gigabitethernet 1/0/3

[SW1-gigabitethernet1/0/3] port link-aggregation group 1

[SW1-gigabitethernet1/0/3] quit

Configure SW2 as we configure SW1

To verify:

[SW1] display link-aggregation summary