Anti-Probing - ZyXEL Communications Prestige 652H series User Manual

Prestige 652H/HW Series User's Guide
SERVICE
SSDP(UDP:1900)
SSH(TCP/UDP:22)
STRMWORKS(UDP:1558)
SYSLOG(UDP:514)
TACACS(UDP:49)
TELNET(TCP:23)
TFTP(UDP:69)
VDOLIVE(TCP:7000)

13.8 Anti-Probing

If an outside user attempts to probe an unsupported port on your Prestige, an ICMP response packet is
automatically returned. This allows the outside user to know the Prestige exists. The Prestige supports anti-
probing, which prevents the ICMP response packet from being sent. This keeps outsiders from discovering
your Prestige when unsupported ports are probed.
Internet Control Message Protocol (ICMP) 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.
Click Firewall, then the Anti Probing tab to open the screen.
13-22
Table 13-5 Predefined Services
Simple Service Discovery Protocol (SSDP) is a discovery service
searching for Universal Plug and Play devices on your home network or
upstream Internet gateways using UDP port 1900.
Secure Shell Remote Login Program.
Stream Works Protocol.
Syslog allows you to send system logs to a UNIX server.
Login Host Protocol used for (Terminal Access Controller Access Control
System).
Telnet is the login and terminal emulation protocol common on the Internet
and in UNIX environments. It operates over TCP/IP networks. Its primary
function is to allow users to log into remote host systems.
Trivial File Transfer Protocol is an Internet file transfer protocol similar to
FTP, but uses the UDP (User Datagram Protocol) rather than TCP
(Transmission Control Protocol).
Another videoconferencing solution.
DESCRIPTION
Firewall Screens