Services Screen - ZyXEL Communications NBG-417N User Manual

The following table describes the labels in this screen.
Table 51 Security > Firewall > General
LABEL
Enable Firewall
Apply
Reset

12.5 Services Screen

If an outside user attempts to probe an unsupported port on your NBG-417N, an ICMP response
packet is automatically returned. This allows the outside user to know the NBG-417N exists. Use
this screen to prevent the ICMP response packet from being sent. This keeps outsiders from
discovering your NBG-417N 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.
Figure 78 Security > Firewall > Services
The following table describes the labels in this screen.
Table 52 Security > Firewall > Services
LABEL
ICMP
Respond to Ping
on
NBG-417N User's Guide
DESCRIPTION
Select this check box to activate the firewall. The NBG-417N 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.
DESCRIPTION
Internet Control Message Protocol 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.
The NBG-417N will not respond to any incoming Ping requests when Disable is
selected. Select LAN to reply to incoming LAN Ping requests. Select WAN to
reply to incoming WAN Ping requests. Otherwise select LAN & WAN to reply to
all incoming LAN and WAN Ping requests.
Chapter 12 Firewall
119