7장. Using MACsec to encrypt layer-2 traffic in the same physical network

Use Media Access Control security (MACsec) to encrypt and authenticate LAN traffic at layer 2. This process helps eliminate the need to encrypt individual services at layer 7.

Media Access Control security secures point-to-point communication between devices. For example, you can configure MACsec on the two hosts connecting your branch and central offices over a Metro-Ethernet connection to increase security.

MACsec is a layer-2 protocol that encrypts and authenticates all LAN traffic. It uses a pre-shared key to establish connections. To change this key, you must update the NetworkManager configuration on all hosts that use MACsec.

MACsec secures different traffic types over the Ethernet links, including:

A MACsec connection uses an Ethernet device, such as an Ethernet network card, Virtual Local Area Network (VLAN), or tunnel device, as a parent. You can either set an IP configuration only on the MACsec device to communicate with other hosts only by using the encrypted connection, or you can also set an IP configuration on the parent device. In the latter case, you can use the parent device to communicate with other hosts using an unencrypted connection and the MACsec device for encrypted connections.

MACsec does not require any special hardware. For example, you can use any switch, except if you want to encrypt traffic only between a host and a switch. In this scenario, the switch must also support MACsec.

That is, you can configure MACsec for two common scenarios:

Using the MACsec security standard for securing communication at the link layer, also known as layer 2 of the Open Systems Interconnection (OSI) model provides the following notable benefits: