ZyXEL Communications Prestige 650ME, User Manual, Page: 88 / 199

Prestige 650ME ADSL Bridge
7-2 NAT
Table 7-1 Services and Port Numbers
SERVICES PORT NUMBER
DNS (Domain Name System) 53
Finger 79
HTTP (Hyper Text Transfer protocol or WWW, Web) 80
POP3 (Post Office Protocol) 110
NNTP (Network News Transport Protocol) 119
SNMP (Simple Network Management Protocol) 161
SNMP trap 162
PPTP (Point-to-Point Tunneling Protocol) 1723
So, if you have a web server at IP address 192.168.1.6 and a FTP server at IP address 192.168.1.7, then you
need to specify port 80 (web) for the server at IP address 192.168.1.6 and port 21 (FTP) for the FTP server
at IP address 192.168.1.7.
A server can support more than one service, e.g., a server can provide both FTP and DNS service, while
another provides only web service. Furthermore, since you need to specify the IP address of a server in the
Prestige, a server must have a fixed IP address and not be a DHCP client whose IP address potentially
changes each time it is turned on.
In addition to servers for specific services, NAT supports a default server. A service request that does not
have a server explicitly designated for it is forwarded to the default server. If the default server is not
defined, the service request is simply discarded.
7.1.1 Applying NAT
You apply NAT via menus 4 or 11.3 as displayed next. Follow the steps below to apply NAT for Internet
access in menu 4.
Step 1. Enter 4 from the main menu to go to Menu 4 - Internet Access Setup .
Step 2. Press [SPACE BAR] and then [ENTER] to select SUA Only in the Network Address
Tranlstaion field.