The Firewall General Screen - ZyXEL Communications AMG1312-T Series User Manual

Chapter 15 Firewall
Anti-Probing
If an outside user attempts to probe an unsupported port on your AMG1312-T Series, an ICMP
response packet is automatically returned. This allows the outside user to know the AMG1312-T
Series exists. The AMG1312-T Series supports anti-probing, which prevents the ICMP response
packet from being sent. This keeps outsiders from discovering your AMG1312-T Series when
unsupported ports are probed.
ICMP
Internet Control Message Protocol (ICMP) is a message control and error-reporting protocol
between a host server and a gateway to the Internet. ICMP uses Internet Protocol (IP) datagrams,
but the messages are processed by the TCP/IP software and directly apparent to the application
user.
DoS Thresholds
For DoS attacks, the AMG1312-T Series uses thresholds to determine when to drop sessions that do
not become fully established. These thresholds apply globally to all sessions. You can use the
default threshold values, or you can change them to values more suitable to your security
requirements.

15.2 The Firewall General Screen

Use this screen to select the firewall protection level on the AMG1312-T Series. Click Security >
Firewall > General to display the following screen.
Figure 85 Security > Firewall > General
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AMG1312-T Series User's Guide