Prestige 304 Broadband Sharing Gateway with
5.4.1 Introduction
SUA (Single User Account) is a ZyNOS implementation of a subset of NAT (Network Address Translation).
5.4.2 The SUA Server Screen
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 a 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.
Default DMZ Server IP Address
In addition to the servers for specified services, NAT supports a default DMZ server. A default DMZ server receives packets from ports that are not specified in this screen.
If you do not assign a Default DMZ Server IP Address, then all packets received for
ports not specified in this screen will be discarded.
5.4.3 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 5-1 Services and Port Numbers
SERVICES | PORT NUMBER |
ECHO | 7 |
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FTP (File Transfer Protocol) | 21 |
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SMTP (Simple Mail Transfer Protocol) | 25 |
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DNS (Domain Name System) | 53 |
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The Advanced Screens |