A common way to ensure confidentiality of data while being transmitted across an Ethernet network would be:

IPSec (Internet Protocol Security) is a suite of protocols that provides cryptographic security services, including confidentiality (encryption), integrity, and authenticity, to IP packets at the network layer, making it an effective solution for securing data in transit over an Ethernet network.

Public Key Infrastructure (PKI) is a system for creating, managing, and distributing digital certificates, which provides the trust framework for secure communication but does not itself encrypt data in transit.

Full disk encryption protects data at rest on a storage device by encrypting the entire drive, but it does not protect data while being transmitted across a network.

RADIUS (Remote Authentication Dial-In User Service) is a networking protocol that provides centralized Authentication, Authorization, and Accounting (AAA) management, but it does not directly encrypt the data payload of user traffic.