User manual

Chapter 2 - Managing a Single Device/Cell Bridging Page
AlvariCRAFT Device Manager 102 User Manual
2.19.1.2 Ethernet Broadcast Filtering (SU and RB Only)
The Ethernet Broadcast Filtering feature enables defining the layer 2 (Ethernet)
broadcast and multicast filtering capabilities of the device. Filtering the Ethernet
broadcasts enhances the security of the system and saves bandwidth on the
wireless medium by blocking protocols that are typically used in the customer's
LAN but are not relevant for other customers, such as NetBios, which is used by
the Microsoft Network Neighborhood. Enabling this feature blocks Ethernet
broadcasts and multicasts by setting the I/G bit at the destination address to 1.
This feature should not be enabled when there is a router behind the SU/RB.
The Ethernet Broadcast Filtering section includes the following parameters:
Roaming Option Applicable only for SU and RB. This parameter defines the roaming
support of the unit. When roaming is not expected, it is preferable to
set this parameter to Disable. This will cause the unit to start scanning
for another AU/BU after losing connectivity with the current AU/BU
only after 7 seconds during which no beacons were received from the
current AU/BU. This will prevent scanning for another AU/BU in cases
where no beacons were received due to a short temporary problem.
When set to Enable, the SU/RB will wait only one second before it
starts scanning for another AU/BU. In addition, when the Roaming
Option is enabled, the SU/RB will send Roaming SNAP messages
upon associating with a new AU/BU. This enables fast distribution of
the new location for all clients that are behind the SU/RB. In this case,
the SU/RB will send multicast SNAP messages via the wireless link
each time it associates with a new AU/BU, except for the first
association after reset. The SU/RB will send one SNAP message for
each client learned on its Ethernet port, based on its bridging table. In
the SNAP message the clients' MAC address is used as the source
address. The AU/BU that receives this SNAP message learns from it
the new location of the clients. It forwards the SNAP to other
AUs/BUs and Layer-2 networking equipment via its Ethernet port, to
facilitate uninterrupted connectivity and correct routing of
transmissions to these clients. The new AU/BU as well as the
previous AU/BU with which the device was associated, will forward
the SNAP messages also to all other SUs/RBs associated with them.
Ethernet Port Control Applicable only for SU and RB. This parameter allows enabling or
disabling non-management traffic to/from the Ethernet port. When
changed to Disable, all current data sessions will be terminated. The
unit is still manageable via the Ethernet port even if it is disabled for
data traffic.