Cambium Networks PMP 450 AP, Руководство по настройке

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Chapter 3: Operation System statistics
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Interpreting Bridging Table statistics
If NAT (network address translation) is not active on the SM/BHS, then the Bridging Table page
provides the MAC address of all devices that are attached to registered SMs/BHS (identified by LUIDs).
The SM/BHS management MAC addresses are also added in bridge table upon SMs/BHS registration.
These entries will be remove automically from the table once SMs/BHS is de-registered. This alleviates
the arp cache > bridge cache timeout problems.
The bridging table allows data to be sent to the correct module as follows:
• For the AP/BHM, the uplink is from RF to Ethernet. Thus, when a packet arrives in the RF interface
to the AP/BHM, the AP/BHM reads the MAC address from the inbound packet and creates a
bridging table entry of the source MAC address on the other end of the
RF interface.
•
For the SM/BHS, the uplink is from Ethernet to RF. Thus, when a packet arrives in the Ethernet
interface to one of these modules, the module reads the MAC address from the inbound packet and
creates a bridging table entry of the source MAC address on the other end of the Ethernet interface.
Figure 88 Bridging Table page
The Bridging Table supports up to 4096 entries.
Interpreting Translation Table statistics
When Translation Bridging is enabled in the AP, each SM keeps a table mapping MAC addresses of
devices attached to the AP to IP addresses, as otherwise the mapping of end-user MAC addresses to IP
addresses is lost. (When Translation Bridging is enabled, an AP modifies all uplink traffic originating
from registered SMs such that the source MAC address of every packet is changed to that of the SM
which bridged the packet in the uplink direction.)