ZyXEL Communications MSAP2000 manual Introduction to MAC Table

MSAP2000 AAMS User’s Guide

CHAPTER 22

MAC Table

This chapter introduces the MAC Table screen.

22.1Introduction to MAC Table

The MAC table lists device MAC addresses that are dynamically learned by the MSAP2000 AAMS. The table shows the following for each MAC address: the port upon which Ethernet frames were received from the device, to which VLAN groups the device belongs (if any) and to which channel it is connected (for devices connected to DSL ports).

The switch uses the MAC table to determine how to forward frames. See the following figure.

1The switch examines a received frame and learns the port on which this source MAC

address came.

2The switch checks to see if the frame's destination MAC address matches a source MAC

address already learned in the MAC table.

•If the switch has already learned the port for this MAC address, then it forwards the frame to that port.

•If the switch has not already learned the port for this MAC address, then the frame is flooded to all ports. Too much port flooding leads to network congestion.

•If the switch has already learned the port for this MAC address, but the destination port is the same as the port it came in on, then it filters the frame.

Figure 69 MAC Table Filtering Flowchart

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