Linkskey LKR-604 - Manual (Page 45)

LKR-604
37
Firewall
The LKR-604 Broadband Router provides extensive Firewall protection
by restricting connection parameters to limit the risk of hacker attacks
and by defending against a wide array of common hacker attacks.
The LKR-604 Broadband Router provides packet filtering rules by
restricting service ports, IP address or MAC address. However, for
applications that require unrestricted access to the Internet, you may
configure a specific client/server as a demilitarized zone (DMZ)
Discard PING From WAN Side
When "Discard PING from WAN side" is checked, it causes the public
WAN IP address on the LKR-604 Broadband Router to ignore ping
commands. Pinging public WAN IP addresses is a common method
used by hackers to test whether the WAN IP address is valid.