ZyXEL Communications ZyXEL ZyAIR 100 - Manual (Page 251)

ZyWALL 10~100 Series Internet Security Gateway
Remote Management Screens 16-13
If an outside user attempts to probe an unsupported port on your ZyWALL, an ICMP response packet is
automatically returned. This allows the outside user to know the ZyWALL exists. The ZyWALL series
support anti-probing, which prevents the ICMP response packet from being sent. This keeps outsiders from
discovering your ZyWALL when unsupported ports are probed.
Figure 16-8 Security
The following table describes the fields in this screen.
Table 16-7 Security
LABEL DESCRIPTION
ICMP 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.
Respond to Ping
on
The ZyWALL 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 (& DMZ if your ZyWALL
has a DMZ port) to reply to both incoming LAN and WAN (and DMZ if present) Ping
requests.