ZyXEL Communications MES-2110 - Manual (Page 151)

MES-2110 User’s Guide
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H A P T E R
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MAC
20.1 Overview
The MAC Table screen (a MAC table is also known as a filtering database) shows
how frames are forwarded or filtered across the MES-2110’s ports. It shows what
device MAC address, belonging to what VLAN group (if any) is forwarded to which
port(s) and whether the MAC address is dynamic (learned by the MES-2110) or
static (manually entered in the Static MAC Forwarding screen).
The MES-2110 uses the MAC table to determine how to forward frames. See the
following figure.
1
The MES-2110 examines a received frame and learns the port on which this
source MAC address came.
2
The MES-2110 checks to see if the frame's destination MAC address matches a
source MAC address already learned in the MAC table.
• If the MES-2110 has already learned the port for this MAC address, then it
forwards the frame to that port.
• If the MES-2110 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.