What is EtherChannel? | Exploring the Benefits of Port Aggregation

EtherChannel groups ports together to create a single strong connection, which we call Port Aggregation. We do this to transfer data more efficiently by evenly spreading it across all the ports.

Combining many physical connections into one logical link makes our network work better and faster. It also becomes much more reliable, making things less likely to go wrong.

What is the Cisco EtherChannel Technology?

Large or small companies need more bandwidth and redundancy. Additionally, it enhances their network connection structure. For these reasons, many cables connect the switches to prevent data loss. In addition, it establishes more than one connection.

Cisco’s EtherChannel makes the network bigger and keeps it steady with help from Kalpana’s improvements. Cisco got even better in the 1990s when they got Kalpana on their team, making them stronger.

Cisco made something cool called EtherChannel to group ports together. This protocol lets them smartly combine FastEthernet or GigabitEthernet ports. After that, they made an even better standard called IEEE 802.3ad. They called it Link and Port Aggregation.

Cisco Layer 2 Switches have default Spanning Tree Protocol. Hence, it prevents network loops from redundant paths. Port Aggregation, or EtherChannel, configures devices to avoid STP blockage. As a result, STP will not block the connection.

Creating many EtherChannel groups between two Switches can cause STP to block one group to prevent loops. But, the STP protocol will stop one of them. Blocking one redundant connection will block the entire structure. So, the group belonging to that port gets blocked.

STP sees one or more physical port connections, divided into logical groups, as just one link.

EtherChannel is an excellent feature that does many valuable things for devices. It helps share the workload, ensures enough bandwidth, and adds a backup just in case. Data moves faster, and delays become smaller when it combines switch ports.

Configuring EtherChannel between switches creates a virtual interface called Port Channel. Furthermore, it enhances network connectivity and performance.

Advantages of EtherChannel

EtherChannel has many advantages in local networks;

• EtherChannel-configured Switch offers redundancy and efficiency in data communication. As a result, network performance and reliability improve.
• There is no need to buy any extra hardware to have more bandwidth. Thus, we logically configure many physical interfaces of the switches to achieve more bandwidth. Example: 8 GigabitEthernet interfaces configured as EtherChannel yield 8 Gb/s bandwidth. So, data transmission benefits from increased speed.
• It provides load balancing in data communication.
• It provides load balancing based on MAC and IP addresses. As a result, it efficiently optimizes traffic distribution.
• When a cable fails, traffic flow continues uninterrupted in the single logical structure. Moreover, Spanning Tree doesn’t need recalculation in such situations.

Configuration Criteria

The port types for EtherChannel must be the same, e.g., FastEthernet and GigabitEthernet interfaces. Therefore, creating them in a single group is not allowed. A group created only between devices with the same port type will be acceptable.

Newer Switch types support up to 8 groups, while older models allow 6. The number can increase based on device structure and hardware performance.

Port Aggregation configures up to 8 ports between two switches in the network. As a result, the total bandwidth reaches 800 Mbps for FastEthernet and 8 Gbps for GigabitEthernet.

The logical grouping process must match both devices. So, for VLANs to pass between them, the port connection should be a trunk for the native VLAN.

How to Configure EtherChannel

We said that EtherChannel makes a single logical connection by combining many physical Ethernet ports. In this case, you can get higher bandwidth, reliability, and high availability.

Now you can track the below steps to configure EtherChannel on Cisco devices:

Before we begin, please note that the steps below apply only to Cisco IOS-based software devices.

1. Identify the physical interfaces you want to create EtherChannel. Usually, these interfaces are at the same speed and are in full duplex mode.
2. It would be best if you used the LACP (Link Aggregation Control Protocol) or PAgP (Port Aggregation Protocol) protocols. Therefore, choose the LACP recommended by Cisco, which is widely used in the industry. Or select the PAgP protocol that works between Cisco devices.
3. Use the following commands to add physical ports to Etherchannel:

configure terminal
interface range gigabitEthernet 0/1 - 4 -> Specify the interfaces you want to include.
channel-group 1 mode desirable -> set to "mode active" if you are going to use LACP. The value "1" is the EtherChannel number, but you can change it.
exitCopy

4. Configure the EtherChannel interface:

interface port-channel 1 -> As an example, specify the number (here 1).
description Port_Channel_Description -> Add a description to the interface.
switchport mode trunk -> Set trunk mode to carry Vlan traffic.
switchport trunk allowed vlan all -> Allow all VLANs.
exitCopy

5. Use the commands below to confirm and save your settings:

show etherchannel summary -> Get information about its status and interfaces' status.
show interface port-channel 1 -> Get more detailed information about the configuration.
write memory -> Finally, save the setup.Copy

Creating EtherChannel on Cisco Switches enables ports to work together. As a result, you get higher bandwidth and redundancy.