ZyXEL Communications P-334W - Manual (Page 204)

Prestige 334W User’s Guide
14-14 Remote Management Screens
Table 14-7 Security
LABEL DESCRIPTION
Respond to Ping
on
The Prestige 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 both incoming LAN and
WAN Ping requests.
Do not respond
to requests for
unauthorized
services
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.
Apply Click Apply to save your customized settings and exit this screen.
Reset Click Reset to begin configuring this screen afresh.