ZyXEL p-660hwp Manual Do Utilizador

 Chapter 11 Firewall Configuration

P-660HWP-Dx User’s Guide

If an outside user attempts to probe an unsupported port on your P-660HWP-Dx, an ICMP 
response packet is automatically returned. This allows the outside user to know the P-
660HWP-Dx exists. The P-660HWP-Dx supports anti-probing, which prevents the ICMP 
response packet from being sent. This keeps outsiders from discovering your P-660HWP-Dx 
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. 
Refer to 

 for more information. 

Click Security > Firewall > Anti Probing to display the screen as shown. 

Figure 107   Firewall: Anti Probing

SSH(TCP/UDP:22)

Secure Shell Remote Login Program.

STRMWORKS(UDP:1558) 

Stream Works Protocol.

SYSLOG(UDP:514)

Syslog allows you to send system logs to a UNIX server.

TACACS(UDP:49) 

Login Host Protocol used for (Terminal Access Controller  Access 

Control System).

TELNET(TCP:23) 

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.

TFTP(UDP:69) 

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).

VDOLIVE(TCP:7000) 

Another videoconferencing solution.

Table 64   Predefined Services (continued)