Operation Manual

ENGLISH
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3.4.6 Virtual Server
Being a natural Internet firewall, the ADSL Router protects your network from being accessed by outside users. When it
needs to allow outside users to access internal servers, e.g. Web server, FTP server, E-mail server or News server, this
product can act as a virtual server. You can set up a local server with specific port number that stands for the service, e.g.
Web (80), FTP (21), Telnet (23), SMTP (25), POP3 (110), DNS (53), ECHO (7), NNTP (119). When an incoming access
request to the router for specified port is received, it will be forwarded to the corresponding internal server.
For example, if you set the Service Port number 80 (Web) to be mapped to the IP Address 192.168.1.2, then all the http
requests from outside users will be forwarded to the local server with IP address of 192.168.1.2.
DMZ: Regarding the DMZ Host, it is a local computer exposed to the Internet. Therefore, an incoming packet will be checked
by Firewall and NAT algorithms in ADSL router, then passed to the DMZ host when packet is not sent by hacker and not
limited by virtual server list.
If you have disabled the ADSL Router’s NAT option in the WAN-ISP section, this Virtual Server function
will hence be invalid.
If the DHCP server option is enabled, you have to be very careful in assigning the IP addresses of the
virtual servers in order to avoid conflicts. The easy way is that the IP address assigned to each virtual
server should not fall into the range of IP addresses that are to be issued by the DHCP server. You
configure the virtual server IP address manually, but it is still in the same subnet with the router.