Chapter 1 Introducing the ZyXEL Device
P-660HW-Tx v3 User’s Guide
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• Hide your wireless network name (SSID). The SSID can be regularly broadcast and
unauthorized users may use this information to access your network. See Chapter 9 on
page 127 for directions on using the web configurator to hide the SSID.
• Enable the MAC filter to allow only trusted users to access your wireless network or deny
unwanted users access based on their MAC address. See Section 9.2.2 on page 128 for
directions on configuring the MAC filter.
1.3.3 Firewall
See Chapter 12 on page 173 for more information on the following security measures.
• Ensure the firewall is turned on. Traffic initiated from your WAN is blocked by default.
• Set the firewall to block ICMP requests.
• Enable do not respond to requests for unauthorized services.
• If you have a backup gateway (for example, backup Internet access) on your network,
disable the Bypass Triangle Routes feature and enable IP Alias to put your backup
gateway on a different subnet.
• Avoid raising the maximum number of NAT sessions per host unnecessarily as it
increases the possibility of unauthorized connections, such as connections caused by a
computer virus.
1.3.4 NAT
• Enable NAT (Network Address Translation) to make devices on your network “invisible”
to those outside your network (unless you configure port-forwarding rules for them).
• Applications such as games or file-sharing can be configured so they are visible from
other networks by using port-forwarding. Ensure only applications you want are
configured to port-forward.
See Chapter 10 on page 147 for instructions on these measures.
1.3.5 Content filter
• You can block web services including cookies, ActiveX and Java. While these services
can be misused, they can also enhance the functionality of a website. To block these
services, follow the instructions in Chapter 13 on page 195.
1.3.6 UPnP
• Disable UPnP (Universal Plug and Play) unless you specifically want applications (for
example, games or file-sharing applications) on your network to pass through your
firewall unchecked.
1.4 Maintaining Your ZyXEL Device
Do the following things regularly to keep your ZyXEL Device running.
• Check the ZyXEL website (www.zyxel.com.tw) regularly for new firmware for your
ZyXEL Device. Ensure you download the correct firmware for your model.
