Port Security
Port security limits which MAC addresses can use a switch port to reduce rogue device risk.
Updated: 2026-03-05
Definition
Port security can restrict a port to a set number of MAC addresses and define what happens on violation.
It helps prevent unauthorized devices from connecting or MAC flooding attacks.
Key points
- Limit MAC addresses per port
- Sticky MAC can learn addresses
- Violation modes: protect/restrict/shutdown
Common mistakes
- Misconfiguring and shutting down valid user ports.
- Not documenting sticky MAC usage (hard to troubleshoot).
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