This article will show you how to Setup Link Aggregation [LAG] on Switch. It will show the differences between Static and LACP and how to configure a switch with LAG. 

 

 

1) What is Link Aggregation [LAG]

Link Aggregation (LAG) is taking two ports and combining /grouping these into one to get higher capacity (speed or reliability) on the link. This is either done by Static or LACP (Link Aggregation Control Protocol). Static LAG is used if you're configuring everything manually (if the ports are configured as static members of a trunk group), while LACP is used when ports are configured to join an already existing trunk group through LACP using the protocol to communicate.

 

1.1 Static Trunk

With a static trunk, several (n) ports are connected to form a logical port with n times the bandwidth. It is imperative that the same static trunk configuration is set on both sides of the trunk (both switches or servers).

 

Benefits

- Group two or up to eight ports as a single virtual link
- Utilize available bandwidth between the switch and other network devices
- Enhance network reliability between network devices

1.2 LACP

Link Aggregation Control Protocol (LACP) is part of an IEEE specification (802.3ad) that allows you to bundle several physical ports together to form a single logical channel.

 

With a LACP (IEEE 802.3AD trunk), several (number n) ports are connected to form a logical port (LAG) with n times the bandwidth. In addition, certain control packets are sent via the Link Aggregation Group (LAG) using the LACP (Link Aggregation Control Protocol). In the event of a line failure, the faulty/damaged line can be automatically removed from the LAG.

 

Benefits
- Allow the switch to negotiate automatically by send LACP packets
- Detect failure even if it's not directly connected to the failure, or remove the link from the group
- Load sharing between ports

 

Type	Static Trunk	LACP
Mechanism	Static binding without packets negotiation	Dynamically negotiated by LACP packets
Pros	No CPU loading	Detect link failure without any physical link down
Cons	Cannot detect link failure	Higher CPU loading due to controlling packets

 

2) Configure Link Aggregation (LAG)

 

NOTE: First configure, then connect!

 

2.1 Check before you start

Check the following:

• Check Port Status, here Example Port 7/8:

Also make sure that the ports are enabled: 

 

Next, check that Loop guard is not active on these Ports. Navigate to: 

SWITCHING > Loop Guard

 

Then hit "Apply"

 

Check that Port Security is disabled on needed Ports by navigating to: 

SECURITY > Port Security

So now we can start to configure Link Aggregation.

 

2.2 Link Aggregation

So now we can start to configure Link Aggregation by navigating to: 

PORT > Link Aggregation > Link Aggregation Setting

Activate the Group ID that you want to use and select the same Group at the ports you want to aggregate. 

 

Info: src-dst-mac to distribute traffic based on a combination of the packet’s source and destination MAC addresses.

 

Select Ports which should be used by (here) T4:

 

Go down and apply the settings.

 

Now Port 7/8 is bound together to a Link Aggregation.

Don’t forget to save the configuration: Switch Configuration Lost After Power Outage or Power Cycle Issue

 

 

 

2.3 Verify Results

You can double-check, go back to Status:

And you can see Trunk is assign to Port 7&8 and ready to use.