3e Technologies International AirGuard 3e-525A-3, Руководство пользователя

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3e–525A–3 Wireless Access Point Chapter 4: Gateway Confi guration
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Virtual Server
Click the entry on the left hand navigation panel for Firewall — Vir-
tual Server .
In order to protect the Private Network, the built-in NAT fi rewall
fi lters out traffi c to the private network. Since all clients on the Pri vate
Net work are normally not visible to outside users, the virtual server func-
tion allows some clients on the Private Net work to be ac cess ed by outside
users by confi guring the application mapping func tion offered on this
page. Certain well known ap pli ca tions use specifi c TCP ports, such as
Telnet (port 23), FTP (port 21), and Web server (port 80). Client com put ers
on the Private LAN can host these ap pli ca tions, and allow users from the
Internet to access these ap pli ca tions hosted on the virtual servers.
This is done by mapping virtual servers to private IP addresses,
according to the specifi c TCP port application. As the planning table
below shows, we have identifi ed a Telnet (port 23) virtual server for
pri vate IP 192.168.15.56, a SMTP Mail (port 25) virtual server for pri-
vate IP 192.168.15.33, and a Web (port 80) virtual server for private IP
192.168.15.64. For example, all Internet requests to the gateway for SMTP
Mail services (port 25) to the WAN IP address will redirected to the Pri-
vate Network computer specifi ed by the server IP 192.168.15.33.
Service Port Server IP
23 192.168.15.56
25 192.168.15.33
80 192.168.15.64