EtherChannel is [Cisco]'s solution to balance the load between multiple paths between two [Ethernet] based devices. As far as I can tell, it is only available on the Cisco [Catalyst] [switch] and Cisco [routers] with certain [IOS] images.

In a traditional [switched network], when you connect two interfaces between two switches, you create a potential loop in which frames can travel forever. This is A BAD THING. With [IEEE]'s [Spanning Tree] [Protocol], this looping problem is avoided by [blocking] one of the ports to form a single, non-looping path. No regular traffic will be able to pass through the blocked ports. This also means that, even if you have two links of 200mbit/s [full-duplex|each], you will still have an effective [bandwidth] of 200mbit/s between the two switches as one of the ports are down.

EtherChannel solves this problem by "bundling" up to eight ports between the two switches into a virtual [interface]. Traffic is [load-balanced] between these [interface]s. This allows for the available bandwidth of all the links to be used while allowing for [redundancy].

EtherChannel is usually deployed as an [uplink] to other switches when there are no higher speed interfaces available. It is low-cost if the equipment already exists.

EtherChannel (thing)