Which protocol would be used to bundle multiple Ethernet ports into a virtual link with an aggregated bandwidth?

The Link Aggregation Control Protocol (LACP) is the standard protocol used for the dynamic creation and management of Link Aggregation Groups (LAGs). LACP, defined in the IEEE 802.1AX standard (formerly IEEE 802.3ad), allows multiple physical Ethernet ports to be bundled together to form a single, high-bandwidth logical link. This aggregation not only increases the total available bandwidth but also provides link-level redundancy. If a physical link within the LAG fails, traffic is automatically redistributed across the remaining active links without disrupting the logical connection.

A. RSTP: Rapid Spanning Tree Protocol (RSTP) is a loop-prevention protocol that blocks redundant links in a switched network, which is contrary to bundling them for aggregated bandwidth.

C. ERP: Ethernet Ring Protection (ERP), defined in ITU-T G.8032, is a protocol designed for high-speed fault recovery and loop prevention in Ethernet ring topologies, not for link aggregation.

D. VRRP: The Virtual Router Redundancy Protocol (VRRP) is a Layer 3 protocol that provides default gateway redundancy by creating a virtual router, and it does not aggregate physical link bandwidth.

1. IEEE Standard 802.1AX-2014

"IEEE Standard for Local and metropolitan area networks--Link Aggregation

" IEEE Standards Association

2014.

Section 1

Clause 1.1 (Scope): "This standard defines a single MAC-independent Link Aggregation technology that allows one or more links to be aggregated together to form a Link Aggregation Group. The Link Aggregation Group operates as a single logical link..."

Section 6

Clause 6.4 (Link Aggregation Control Protocol): Details the operation of LACP for automatically configuring

maintaining

and monitoring Link Aggregation.

2. Ericsson IP Operating System CLI Reference

"Configuring Link Aggregation

" Document Number: 2/221 04-FAP 130 304 Uen Rev D.

Chapter: Link Aggregation: "Link aggregation is a method of grouping one or more physical links between two systems to form a single logical link

known as a Link Aggregation Group (LAG)... LACP is used to exchange information with the partner system to form a LAG."

3. Stallings

W.

"Data and Computer Communications

" 10th ed.

Pearson

2014. (Widely used in university curricula).

Chapter 16.4 (Link Aggregation): "The Link Aggregation Control Protocol (LACP) is defined in IEEE 802.1AX. LACP is designed to be used to manage the assignment of links to a link aggregation group." This text is a staple in networking courses at reputable institutions.