Cambium Networks cnReach N500, User Manual

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cnReach N500 User Guide System Configuration
phn-4673_003v000 (November 2018)
2-68
Diagnostics/Forwarding Table
The Forwarding Table is a dynamic table that maps device MAC addresses to ports/interfaces on the
radio.
It is used to identify the forwarding port/interface that the input port/interface should forward an
Ethernet frame
The Forwarding Table exists on the Data Link Layer of the OSI Model and contains the Ethernet packet
as well as source and destination MAC addresses.
When the radio receives an Ethernet frame with a destination address in the Forwarding Table, it sends
the frame out of the port/interface stored in the Forwarding Table.
The first time the radio sees the MAC address, it treats the frame as a broadcast and sends it out of all
active ports/interfaces except for the interface where the frame was received.
Without a Forwarding Table, all Ethernet frames received by the radio would be sent out of all other
ports (including RF Modules, which would eat up RF bandwidth).
The Forwarding Table allows the radio to send an Ethernet frame only out of the port/interface where
the destination device is located.
Local designates whether the MAC address is contained within the radio.
Age designates how much time has passed since the MAC address was resolved.