Filter
Top Products
ZyWALL 2 Series User’s Guide
NAT 8-5
8.2.1 SUA (Single User Account) Versus NAT
SUA (Single User Account) is an implementation of a subset of NAT that supports two types of mapping,
Many-to-One and Server. The ZyWALL also supports Full Feature NAT to map multiple global IP
addresses to multiple private LAN IP addresses of clients or servers using mapping types. Select either SUA
Only or Full Feature in WAN IP.
8.3 SUA Server
A SUA server set is a list of inside (behind NAT on the LAN) servers, for example, web or FTP, that you can
make visible to the outside world even though SUA makes your whole inside network appear as a single
computer to the outside world.
You may enter a single port number or a range of port numbers to be forwarded, and the local IP address of
the desired server. The port number identifies a service; for example, web service is on port 80 and FTP on
port 21. In some cases, such as for unknown services or where one server can support more than one service
(for example both FTP and web service), it might be better to specify a range of port numbers. You can
allocate a server IP address that corresponds to a port or a range of ports.
Many residential broadband ISP accounts do not allow you to run any server processes (such as a Web or
FTP server) from your location. Your ISP may periodically check for servers and may suspend your account
if it discovers any active services at your location. If you are unsure, refer to your ISP.
8.3.1 Default Server IP Address
In addition to the servers for specified services, NAT supports a default server IP address. A default server
receives packets from ports that are not specified in this screen.
If you do not assign a Default Server IP Address, the ZyWALL discards all packets
received for ports that are not specified here or in the remote management setup.
8.3.2 Port Forwarding: Services and Port Numbers
The most often used port numbers are shown in the following table. Please refer to RFC 1700 for further
information about port numbers. Please also refer to the Supporting CD for more examples and details on
SUA/NAT.
Table 8-3 Services and Port Numbers
SERVICES PORT NUMBER
ECHO 7
FTP (File Transfer Protocol) 21
SMTP (Simple Mail Transfer Protocol) 25