Link aggregation allows network devices to________

Link aggregation, as defined by the IEEE 802.3ad standard, is a method of combining or "binding" multiple physical network links into a single logical channel. This technique serves two primary purposes: increasing the total available bandwidth beyond the capacity of any single link and providing link redundancy. By bundling physical interfaces, network devices can treat them as a single, higher-capacity link, effectively distributing traffic across the member interfaces to achieve greater throughput and resilience against individual link failures.

A. This statement is imprecise. Link aggregation does not increase the bandwidth of an individual physical interface; it creates a new logical interface with the combined bandwidth of its members.

C. The primary function of link aggregation is to increase bandwidth, not restrict it. Bandwidth restriction is typically managed by traffic shaping or quality of service (QoS) policies.

D. This is incorrect because option B provides an accurate and specific description of the function of link aggregation.

1. Fortinet FortiOS 7.4.0 Administration Guide

System > Interfaces > Aggregate interfaces

Page 1019.

The documentation states: "An aggregate interface is a virtual interface that combines multiple physical interfaces into a single logical interface. This allows you to increase the bandwidth and provide link redundancy between two devices." This directly supports the concept of binding physical interfaces to increase bandwidth.

2. Fortinet Cookbook

Link Aggregation (802.3ad)

Document ID: FD35564.

The article specifies: "Link aggregation combines two or more physical links into a single logical link. This logical link has the bandwidth of all the physical links combined." This confirms that the method involves combining physical links into a single channel to increase bandwidth.

3. Fortinet Knowledge Base

Technical Tip: Link Aggregation Group (LAG) on FortiGate

Document ID: FD50290.

This technical tip explains: "Link Aggregation Group (LAG) is used to bundle multiple physical links into a single logical link to increase the overall throughput and provide redundancy." This reinforces that the purpose is to increase bandwidth by bundling physical links.