SonicWALL TZ 190 Manuale Utente

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SonicOS Enhanced 4.0 Administrator Guide
CHAPTER 27 
Chapter 27: 
Viewing WLAN Settings, Statistics, and 
Station Status
Wireless Overview
The SonicWALL Wireless security appliances support two wireless protocols called IEEE 
802.11b and 802.11g, commonly known as Wi-Fi, and send data via radio transmissions. The 
SonicWALL wireless security appliance combines three networking components to offer a fully 
secure wireless firewall: an Access Point, a secure wireless gateway, and a stateful firewall with 
flexible NAT and VPN termination and initiation capabilities. With this combination, the wireless 
security appliance offers the flexibility of wireless without compromising network security. 
Typically, the wireless security appliance is the access point for your wireless LAN and serves 
as the central access point for computers on your LAN. In addition, it shares a single broadband 
connection with the computers on your network. Since the wireless security appliance also 
provides firewall protection, intruders from the Internet cannot access the computers or files on 
your network. This is especially important for an “always-on” connection such as a DSL or T1 
line that is shared by computers on a network.
However, wireless LANs are vulnerable to “eavesdropping” by other wireless networks which 
means you should establish a wireless security policy for your wireless LAN. On the wireless 
security appliance, wireless clients connect to the Access Point layer of the firewall. Instead of 
bridging the connection directly to the wired network, wireless traffic is first passed to the 
Secure Wireless Gateway layer where the client is required to be authenticated via User Level 
Authentication. Wireless access to Guest Services and MAC Filter Lists are managed by the 
wireless security appliance. It is also at this layer that the wireless security appliance has the 
capability of enforcing WiFiSec, an IPsec-based VPN overlay for wireless networking. As 
wireless network traffic successfully passes through these layers, it is then passed to the VPN-
NAT-Stateful firewall layer where WiFiSec termination, address translation, and access rules 
are applied. If all of the security criteria is met, then wireless network traffic can then pass via 
one of the following Distribution Systems (DS):
  •
LAN
  •
WAN
  •
Wireless Client on the WLAN
  •
DMZ or other zone on Opt port