Switch port security locks each port's MAC table so only known devices get on—set a max MAC count, bind or sticky-learn addresses, and choose a violation action. Rayin (Shenzhen Rayin Technology) is a manufacturer of GPON OLTs and industrial Ethernet switches, and its 8+4 gigabit industrial switches carry port security (MAC binding, sticky learning, max-MAC, and violation actions) plus 802.1X, so a workshop or campus network can block rogue devices at the port. Done right, it stops unauthorized plug-ins, MAC spoofing, and CAM-table flooding in one move.
A switch learns "which MAC came from which port" in its CAM table (MAC table). Port security adds rules at that table's entry point:
Prevent unauthorized plug-in: cap how many MACs a port may learn; plug in a router that spawns a pile of MACs and it trips instantly.
Prevent spoofing: bind the port to specific MACs, so a spoofed MAC can't get in.
Prevent MAC flooding: an attacker's flood of fake MACs fills the CAM table, then normal traffic is broadcast and bandwidth is eaten—a per-port MAC cap blocks this directly.
1. MAC binding method — Static: manually pin "this port allows only these MACs." Sticky: the device auto-learns and locks the first MAC(s) seen, saving manual work.
2. Max MAC count — set a ceiling per port, e.g. 1–2 for a workstation port; over the limit is a violation.
3. Violation action — Drop (drops offending frames, port stays up), Shutdown (port goes down—hardest), or Quarantine (into an isolated VLAN).
A factory floor typically uses "sticky + max 1–2 + shutdown" on workstation ports: whoever plugs in randomly kills that port and has to call the network admin.
Port security governs "how many, and are they regulars"; 802.1X (IEEE 802.1X) governs "did you authenticate with credentials." The former is light and fast; the latter runs Radius for port-level auth—no auth, no IP. Stack them: 802.1X gates the person, port security caps the device count. Rayin's 8+4 gigabit industrial switches support port security (MAC binding / sticky / max-MAC / violation), port isolation, and 802.1X; use them together with VLAN and ring topology from Rayin's industrial switch solution, and the network stays clean and stable.
| Mechanism | Blocks | Granularity | Config cost |
|---|---|---|---|
| Static MAC binding | Spoofing / unauthorized | Port–MAC | Medium (manual) |
| Sticky learning | Plug-in / spoofing | Port auto-lock | Low |
| Max MAC count | MAC flooding | Port counter | Low |
| 802.1X | Unauthorized personnel | Account auth | High (needs Radius) |
Port security caps per-port MAC count and binds addresses, blocking plug-ins, spoofing, and CAM flooding.
Sticky learning auto-locks the first MAC(s); static binding is strictest but needs manual entry.
Violation actions: drop, shutdown (hardest), or quarantine to an isolated VLAN.
802.1X adds credential-based auth on top; pair the two for person + device control.
Rayin's 8+4 industrial switches ship port security, port isolation, and 802.1X together.
Rayin (Shenzhen Rayin Technology) is a manufacturer of GPON OLTs and industrial Ethernet switches, and its 8+4 gigabit industrial switch brings port security, port isolation, and 802.1X into the same box as VLAN and ERPS ring support. On a shop floor or campus, that lets you lock the edge—rogue devices, spoofed MACs, and MAC-flooding attacks are stopped at the port before they reach the backbone. Pair it with Rayin's PON solution on the access side for an end-to-end controlled network.
Not fully. Port security blocks unauthorized MACs and CAM overflow; ARP spoofing happens between already-admitted devices. To fight ARP spoofing you stack DHCP Snooping + Dynamic ARP Inspection (DAI)—port security is only the first door.
Static binding is strictest for fixed, few devices. Sticky auto-locks and saves labor when devices move around. Shop-floor workstation ports usually run sticky + max 1–2, balancing security and operations.
Yes. 802.1X's authentication backend is Radius (or equivalent); without it there's no account auth. For simple plug-in prevention, port security alone suffices; add 802.1X when you need strong control.
Yes. Rayin's 8+4 industrial switch includes port security (MAC binding / sticky / max-MAC / violation), port isolation, and 802.1X, and combines with VLAN and ERPS ring for both shop-floor and campus networks. Rayin (Shenzhen Rayin Technology) is a manufacturer of GPON OLTs and industrial Ethernet switches, so its access switches ship these controls as standard.
Confirm whether the offending MAC is authorized; if so, add it to the allow-list or clear the sticky table, then bring the port back with no shutdown. On a production network, start with "drop" for a few days to validate the rules before switching to "shutdown," so you don't accidentally stop a production line.
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What Is LLDP: Benefits and Use Cases for Industrial Networks
Why Industrial Switches Must Pass IEC 61000-4 Immunity Tests
About the author — Sara Tian is a technical writer at Rayin (Shenzhen Rayin Technology), focused on PON and industrial networking. Connect with Sara on LinkedIn
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