Figure 13-12 Anti-Probing; Table 13-6 Anti-Probing - ZyXEL Communications Prestige 652H series User Manual

The following table describes the labels in this screen.
LABEL
Respond to PING
on
Do not Respond to
Requests for
Unauthorized
Services.
Back
Apply
Cancel
Firewall Screens

Figure 13-12 Anti-Probing

Table 13-6 Anti-Probing

The Prestige does 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. Select DMZ to reply to incoming DMZ Ping requests.
Otherwise select LAN & WAN & DMZ to reply to both incoming LAN and WAN and
DMZ Ping requests.
Select this option to prevent hackers from finding the Prestige by probing for unused
ports. If you select this option, the Prestige will not respond to port request(s) for
unused ports, thus leaving the unused ports and the Prestige unseen. By default this
option is not selected and the Prestige will reply with an ICMP Port Unreachable
packet for a port probe on its unused UDP ports, and a TCP Reset packet for a port
probe on its unused TCP ports.
Note that the probing packets must first traverse the Prestige 's firewall mechanism
before reaching this anti-probing mechanism. Therefore if the firewall mechanism
blocks a probing packet, the Prestige reacts based on the firewall policy, which by
default, is to send a TCP reset packet for a blocked TCP packet. You can use the
command "sys firewall tcprst rst [on|off]" to change this policy. When the firewall
mechanism blocks a UDP packet, it drops the packet without sending a response
packet.
Click Back to return to the Firewall Functions screen.
Click Apply to save your changes back to the Prestige.
Click Cancel to begin configuring this screen afresh.
Prestige 652H/HW Series User's Guide
DESCRIPTION
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