The Power and Flexibility of Junos' Aggregated Ethernet Interfaces

In the world of networking, the ability to aggregate multiple physical Ethernet links into a single logical link is a powerful tool. This technique, known as link aggregation, can provide increased bandwidth, improved redundancy, and load balancing capabilities. In Juniper Networks' Junos operating system, this is achieved through the use of Aggregated Ethernet (AE) interfaces. In this blog post, we will delve into the power and flexibility of Junos' AE interfaces, a topic that is crucial for students studying for the JNCIS-ENT certification.

What are Aggregated Ethernet Interfaces?

Aggregated Ethernet interfaces in Junos are logical interfaces that represent one or more physical Ethernet interfaces. These physical interfaces, known as member links, are bundled together to form a single, logical link that operates as if it were a single, high-bandwidth, reliable link.

Configuring Aggregated Ethernet Interfaces

Configuring AE interfaces in Junos is a straightforward process. First, you need to configure the physical interfaces that will be part of the AE bundle. Here's an example:

set interfaces ge-0/0/0 gigether-options 802.3ad ae0
set interfaces ge-0/0/1 gigether-options 802.3ad ae0

In this example, the physical interfaces ge-0/0/0 and ge-0/0/1 are configured to be part of the AE interface ae0.

Next, you need to configure the AE interface itself. Here's an example:

set interfaces ae0 aggregated-ether-options minimum-links 1
set interfaces ae0 unit 0 family inet address

In this example, the AE interface ae0 is configured with a minimum of 1 link (meaning the AE interface will be up as long as at least one member link is up) and an IP address of

The Power of Aggregated Ethernet Interfaces

The power of AE interfaces lies in their ability to provide increased bandwidth and improved redundancy. By aggregating multiple physical links into a single logical link, you can effectively multiply the bandwidth of the logical link. For example, if you aggregate four 1Gbps links into a single AE interface, you effectively have a 4Gbps link.

In addition, AE interfaces provide improved redundancy. If one member link fails, the AE interface continues to operate, albeit with reduced bandwidth. This can be crucial in situations where network uptime is critical.

The Flexibility of Aggregated Ethernet Interfaces

AE interfaces are also incredibly flexible. You can add or remove member links from an AE interface without causing the interface to go down. This allows you to dynamically adjust the bandwidth of the AE interface to meet changing network demands.

In addition, Junos supports flexible load balancing across member links. This means you can distribute network traffic across the member links in a way that best suits your network's needs.


Aggregated Ethernet interfaces in Junos are a powerful and flexible tool for network engineers. They provide increased bandwidth, improved redundancy, and flexible load balancing capabilities. Understanding how to configure and use AE interfaces is a crucial skill for anyone studying for the JNCIS-ENT certification.

Remember, practice makes perfect. So, don't just read about AE interfaces, get hands-on experience configuring and using them in a lab environment. Happy studying!

© Ben Jacobson.RSS