To access Advanced configuration settings for the SonicWALL wireless security appliance, log
into the SonicWALL, click Wireless
, and then Advanced
. The Wireless > Advanced
page is only available when the SonicWALL is acting as an access point.
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1.
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Select
Hide SSID in Beacon
. Suppresses broadcasting of the SSID name and disables responses to probe requests. Checking this option helps prevent your wireless SSID from being seen by unauthorized wireless clients.
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2.
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Type a value in milliseconds for the
Beacon Interval
. Decreasing the interval time makes passive scanning more reliable and faster because Beacon frames announce the network to the wireless connection more frequently.
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The following other advanced settings can be configured.
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Step 1
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Enable Short Slot Time
: Select Enable Short Slot Time
to increase performance if you only expect 802.11g traffic. 802.11b is not compatible with short slot time.
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Step 2
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The
Antenna Diversity
setting determines which antenna the wireless security appliance uses to send and receive data.
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Step 3
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Select
Full Power
from the Transmit Power
menu to send the strongest signal on the WLAN. For example, select Full Power
if the signal is going from building-to-building. Half Power
is recommended for office-to-office within a building, and Quarter Power
or Eighth Power
are recommended for shorter distance communications.
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Step 4
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Select
Short
or Long
from the Preamble Length
menu. Short
is recommended for efficiency and improved throughput on the wireless network.
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Step 5
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The
Fragmentation Threshold (bytes)
is 2346 by default. Increasing the value means that frames are delivered with less overhead but a lost or damaged frame must be discarded and retransmitted.
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Step 6
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The
RTS Threshold (bytes)
is 2346 by default. If network throughput is slow or a large number of frame retransmissions is occurring, decrease the RTS threshold to enable RTS clearing.
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Step 7
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The default value for the
DTIM Interval
is 1. Increasing the DTIM Interval value allows you to conserve power more effectively.
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Step 8
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The
Association Timeout (seconds)
is 300 seconds by default, and the allowed range is from 60 to 36000 seconds. If your network is very busy, you can increase the timeout by increasing the number of seconds in the Association Timeout (seconds)
field.
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Step 9
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Set the
Maximum Client Associations
to limit the number of stations that can connect wirelessly at one time. The default is 128.
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Step 10
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Data Rate
: Select the speed at which the data is transmitted and received. Best
automatically selects the best rate available in your area given interference and other factors. Or you can manually select a data rate.
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Step 11
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Protection Mode
: Protection can decrease collisions, particularly where you have two overlapping SonicPoints. However, it can slow down performance. Auto
is probably the best setting, as it will engage only in the case of overlapping SonicPoints.
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Step 12
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Protection Rate
: The protection rate determines the data rate when protection is on. The slowest rate offers the greatest degree of protection but the slowest data transmission rate. Choose 1 Mbps
, 2 Mbps
, 5 Mbps
, or 11 Mbps
.
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Step 13
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Protection Type
: Select the type of handshake used to establish a wireless connection: CTS-
only
or RTS-CTS
. 802.11b traffic is only compatible with CTS
.
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Step 14
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Click
Apply
in the top right corner of the page to apply your changes to the security appliance.
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Click
Restore Default
to return the radio settings to the default settings.
The dual antenna wireless SonicWALL security appliances employ two 5 dBi antennas running
in diversity mode. The default implementation of diversity mode means that one antenna acts as a transmitting, and both antennas act as potential receiving antenna. As radio signals arrive at both antennas on the secure wireless appliance, the strength and integrity of the signals are evaluated, and the best received signal is used. The selection process between the two antennas is constant during operation to always provide the best possible signal. To allow for external (higher gain uni-directional) antennas to be used, antenna diversity can be disabled.
The SonicWALL NSA 220 and 250M wireless security appliances employ three antennas. The
Antenna Diversity is set to Best
by default, this is the only setting available for these appliances.
The
Antenna Diversity
setting determines which antenna the wireless security appliance uses to send and receive data. You can select:
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•
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Best
: This is the default setting. When Best
is selected, the wireless security appliance automatically selects the antenna with the strongest, clearest signal. In most cases, Best
is the optimal setting.
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1
: Select 1
to restrict the wireless security appliance to use antenna 1 only. Facing the rear of the appliance, antenna 1 is on the left, closest to the console port. You can disconnect antenna 2 when using only antenna 1.
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•
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2
: Select 2
to restrict the wireless security appliance to use antenna 2 only. Facing the rear of the appliance, antenna 2 is on the right, closest to the power supply. You can disconnect antenna 1 when using only antenna 2.
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