Services Screen - ZyXEL Communications NBG-419N User Manual

19.5 Services Screen

If an outside user attempts to probe an unsupported port on your NBG-419N, an ICMP response
packet is automatically returned. This allows the outside user to know the NBG-419N exists. Use
this screen to prevent the ICMP response packet from being sent. This keeps outsiders from
discovering your NBG-419N 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 104 Security > Firewall > Services
The following table describes the labels in this screen.
Table 65 Security > Firewall > Services
LABEL
ICMP
Respond to Ping
on
Apply
Enable Firewall Rule
NBG-419N User's Guide
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-419N 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.
Click Apply to save the settings.
Chapter 19 Firewall
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