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📡Networking Lessons
Lesson 34 / 39

Viewing the MAC Address Table with show mac address-table

When you want to know which device is on which port by MAC address, use show mac address-table. It displays the mapping the switch has learned between ports and the MAC addresses of connected devices.

The syntax is show mac address-table, in privileged EXEC mode.

Running show mac address-table lists VLAN numbers, MAC addresses, and the port each address was learned on — letting you pin down which device hangs off which port.

A common stumble is checking right after moving a device to a different port: stale entries can linger for a while, so the table may not match the latest physical reality.

In real work, it is a favorite for failure investigations and for hunting down suspicious devices: "where exactly is the machine with this MAC address plugged in?"

Networking
Try it (type this into the pseudo terminal)
show mac address-table

🧑‍💻 You can type this command into the Networking pseudo terminal to try it yourself (this page itself has no interactive terminal).

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