Network Security
Network encryption is well understood at Layer 3 and above. IPsec, TLS, and DTLS are mature protocols organizations deploy routinely to protect traffic traversing untrusted networks.
What is less commonly addressed is the physical link itself. MACsec encrypts Ethernet frames at Layer 2 on the wire between two directly connected devices before traffic enters the network fabric.
Hardware-accelerated Layer 2 encryption with negligible performance impact.
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Organizations that treat dark fiber, leased wavelengths, and campus interconnects as secure because they are physically controlled are relying on trust assumptions rather than cryptographic protection.
Physical isolation is not a security control in the cryptographic sense. It is a trust assumption.
MACsec and IPsec are frequently confused but address different layers and different threat models.
Encrypts individual Ethernet frames on a single physical link between directly connected devices. Operates at line rate on supported hardware with negligible latency overhead. Right control for dark fiber, leased wavelengths, and high-speed campus interconnects.
Creates logical tunnels between two endpoints that may not be directly connected. Protects traffic across multiple hops over untrusted networks. Right control for WAN connectivity across the internet or untrusted carrier networks.
What organizations achieve with MACsec deployment.
Encryption with negligible latency overhead on hardware-accelerated platforms.
Defense against physical interception on dark fiber, leased wavelengths, and campus interconnects.
Additional layer of protection for environments already running IPsec at Layer 3.
Strengthened compliance for regulations requiring encryption of regulated data in transit.
Recommendation: keep to one or two short sentences.
Deep experience with MACsec-capable platforms and deployment considerations.
Extensive experience with enterprise switching and routing platforms that support MACsec acceleration.
Comprehensive approach to MACsec implementation and monitoring considerations.
Planning for hardware compatibility, monitoring tap relocation, and operational impact assessment.
Review related solution pages, supporting materials, and additional resources that help explain where this solution fits and how it can be applied.
Common questions about MACsec Layer 2 encryption.
On hardware that supports MACsec acceleration (most current-generation enterprise switching and routing platforms), performance impact is negligible. Encryption and decryption happen in dedicated ASICs at line rate. Latency overhead is typically measured in microseconds.
MACsec is transparent to Layer 3 and above. VLANs, LACP port channels, routing protocols, and other network protocols operate normally across MACsec-encrypted links. The encryption is applied and removed at the physical interface.
Passive taps on MACsec-encrypted links will capture encrypted frames. Monitoring use cases that depend on passive capture need to be relocated to SPAN or monitoring ports on the network devices, where decrypted traffic is available. This is a deployment consideration to plan for, not a reason to avoid MACsec.
Yes. MACsec requires hardware support on both devices connected by the link. Confirming hardware support at both ends before planning deployment avoids discovering incompatibilities during implementation.
MACsec provides Layer 2 encryption for direct physical links, while IPsec creates Layer 3 tunnels across multiple hops. MACsec is ideal for dark fiber and campus interconnects, while IPsec is better for WAN connectivity. They complement each other in a defense-in-depth strategy.
MACsec helps meet compliance requirements for encryption of regulated data in transit, including healthcare (HIPAA), financial services (PCI DSS), and government regulations. It provides cryptographic protection for internal network segments that may be subject to data protection requirements.
