What is MACsec?
Security at the Ethernet level
Media Access Control Security (MACsec) is the IEEE 802.1AE standard for port-based access control, and the encryption and authentication of Ethernet frames. It secures data traffic between devices such as switches, routers and servers, mitigating eavesdropping and man-in-the-middle attacks. Unlike encryption protocols such as TLS and IPsec, MACsec offers built-in protection directly at the Ethernet level, making it ideal for securing sensitive data in LANs, data centers and backbone infrastructure.
Layer 2 protection for complex environments
MACsec shields data from threats, even in networks running legacy services or unmanaged segments.
MACsec prevents attacks such as sniffing, replay or manipulation with virtually no changes to the existing network architecture.
A secure foundation for data transmission
MACsec has gained importance as organizations increasingly rely on complex software-defined networks and automated infrastructures.
How does MACsec work?
MACsec encrypts and authenticates Ethernet frames between devices, protecting all content except the source and destination MAC addresses. Secure associations (SAs), secure channels (SCs) and security entities (SecYs) form the core of its model. A SecY on each port separates unsecured from secured traffic and manages encryption and decryption. Each unidirectional secure channel (SC) – identified by its secure channel identifier (SCI) – hosts up to four active SAs so keys can rotate without interruption. When end‑to‑end protection must span multiple public hops, VLANs can stay in the clear (VLAN bypass), letting transit networks forward frames with the service tag (S‑Tag) and customer tag (C‑Tag).
MACsec protects Ethernet connections with AES-GCM encryption
Our FSP 150 with ConnectGuard™ uses a dedicated protocol for key negotiation, delivering strong MACsec protection even across public networks.
Why is MACsec important for today’s networks?
MACsec integrates seamlessly into SDN environments and supports automated security policies across edge, cloud and hybrid infrastructures. In an era of zero trust, cloudification and increasing cyber threats, closing security gaps in the physical network structure is essential. MACsec offers robust, transparent protection, even for environments once considered secure, such as internal LANs or data center backbones. Organizations benefit from reduced manual effort, lower latency and cost-efficient Layer 2 encryption. Adva Network Security solutions embed MACsec across the portfolio, giving operators a turnkey path to Layer 2 protection.
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