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

Ethernet Interface Configuration

Below commands run in System-view

interface GigabitEthernet1/0/1

description text

duplex { auto | full | half }

auto by default.

speed { 10 | 100 | 1000 | auto }

By default, the port speed is in the auto-negotiation mode.

Shutdown

By default, an Ethernet interface is in up state.

10-Gigabit Ethernet ports do not support the duplex command or the speed command.

To enable the Jumbo Frame

interface GigabitEthernet1/0/1

jumboframe enable

By default, the device allows jumbo frames with the length of 9.216 bytes to pass

through all Layer 2 Ethernet interfaces.

To reset the counters

reset counters interface

Flow control helps to avoid packet drops on the link. If congestion occurs at the receiving end, it sends pause frame to sending end to stop sending the packet.

interface GigabitEthernet1/0/1

Flow control

Physical link has two states, up and down. Each time the physical link of an interface goes up or down, the physical layer reports to the upper layer and upper layer handles the change which results in increasing the overhead. We can configure link-down suppression to delay the reporting of link down events on an Ethernet interface.

interface GigabitEthernet1/0/1

Link delay

By default link delay is disabled.

Displaying and Maintaining an Ethernet Interface (Available in any view)

Display the current state of an interface and the related information 

display interface GigabitEthernet1/0/1

Display the summary of an interface

display brief interface GigabitEthernet1/0/1