ZyXEL Communications Corporation AMG1302 Manuel D’Utilisation

Chapter 10 Firewalls

AMG1302-T10A User’s Guide

If an outside user attempts to probe an unsupported port on your Device, an ICMP response packet 

is automatically returned. This allows the outside user to know the Device exists. The Device 

supports anti-probing, which prevents the ICMP response packet from being sent. This keeps 

outsiders from discovering your Device when unsupported ports are probed. 

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. 

Use this screen to configure the firewall settings. Click Security > Firewall to display the following 

screen.

Security > Firewall > General