The Firewall General Screen; The Firewall Services Screen - ZyXEL Communications NBG5715 User Manual

Don't enable any local service (such as NTP) that you don't use. Any enabled service could present
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a potential security risk. A determined hacker might be able to find creative ways to misuse the
enabled services to access the firewall or the network.
For local services that are enabled, protect against misuse. Protect by configuring the services to
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communicate only with specific peers, and protect by configuring rules to block packets for the
services at specific interfaces.
Protect against IP spoofing by making sure the firewall is active.
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Keep the firewall in a secured (locked) room.
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17.2 The Firewall General Screen

Use this screen to enable or disable the NBG5715's firewall, and set up firewall logs. Click Security
> Firewall to open the General screen.
Figure 74 Security > Firewall > General l
The following table describes the labels in this screen.
Table 52 Security > Firewall > General
LABEL
Enable Firewall
Apply
Reset

17.3 The Firewall Services Screen

If an outside user attempts to probe an unsupported port on your NBG5715, an ICMP response
packet is automatically returned. This allows the outside user to know the NBG5715 exists. Use this
screen to prevent the ICMP response packet from being sent. This keeps outsiders from discovering
your NBG5715 when unsupported ports are probed.
You can also use this screen to enable service blocking, enter/delete/modify the services you want
to block and the date/time you want to block them.
Click Security > Firewall > Services. The screen appears as shown next.
NBG5715 User's Guide
DESCRIPTION
Select this check box to activate the firewall. The NBG5715 performs access
control and protects against Denial of Service (DoS) attacks when the firewall is
activated.
Click Apply to save the settings.
Click Reset to start configuring this screen again.
Chapter 17 Firewall
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