Billion Electric Company MYGUARD 7500GL Benutzerhandbuch

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myGuard 7500GL 802.11g Security ADSL Router 
 
Chapter 4: Configuration 
 
 
 
161 TCP 
SNMP 
443 
TCP & UDP 
HTTPS 
1503 TCP 
T.120 
1720 TCP 
H.323 
4000 TCP 
ICQ 
7070 UDP 
RealAudio 
 
Because NAT can act as a “natural” Internet firewall, your router protects your network from 
being accessed by outside users when using NAT, as all incoming connection attempts will 
point to your router unless you specifically create Virtual Server entries to forward those ports to 
a PC on your network. When your router needs to allow outside users to access internal servers, 
e.g. a web server, FTP server, Email server or game server, the router can act as a “virtual 
server”. You can set up a local server with a specific port number for the service to use, e.g. 
web/HTTP (port 80), FTP (port 21), Telnet (port 23), SMTP (port 25), or POP3 (port 110), When 
an incoming access request to the router for a specified port is received, it will be forwarded to 
the corresponding internal server.  
For example, if you set the port number 80 (Web/HTTP) to be mapped to the IP Address 
192.168.1.2, then all incoming HTTP requests from outside users will be forwarded to the local 
server (PC) with the IP address of 192.168.1.2. If the port is not listed as a predefined 
application, you need to add it manually. 
In addition to specifying the port number to be used, you will also need to specify the protocol 
used. The protocol used is determined by the particular application. Most applications will use 
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