ZyXEL Prestige 660HW-D1 Wireless Router 91-004-593003B Manual Do Utilizador

P-660H/HW-D Series User’s Guide

Chapter 10 Firewall Configuration

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

 for more information. 

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

Figure 96   Firewall: Anti Probing

SSDP(UDP:1900)

Simole Service Discovery Protocol (SSDP) is a discovery service 

searching for Universal Plug and Play devices on your home network 

or upstream Internet gateways using DUDP port 1900. 

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 61    Predefined Services (continued)