3Com OfficeConnect User Manual page 49

Creating a Virtual DMZ
A virtual DMZ (De-Militarized Zone) Host is a computer on your
network with reduced protection provided by the firewall. This
feature allows a single computer to be exposed to 2-way
communication from outside of your network in One-to-Many
NAT mode. The PC is still protected against DoS and hacker
attacks.
CAUTION: This feature should be used only if the Virtual Server
or Special Applications options do not provide the level of access
needed for certain applications.
To specify one of your computers as a DMZ host, select Redirect
Request to Virtual DMZ Host and enter the IP address of the
computer in the IP Address of DMZ Host text box, and then click
SAVE.
Creating a Virtual Server
Activating and configuring a virtual server allows one or more of
the computers on your network to function as an Internet service
host. For example, one of your computers could be configured as
an FTP host, allowing others outside of your office network to
download files of your choosing. Or, if you have created a Web
site, you can configure one of your computers as a Web server,
so that others can view your Web site.
If you are using One-to-Many NAT you can only have one server
of each type on your network. To have more than one server of
a type (for example more than one web server) visible to the
Internet you must be using One-to-One NAT.
To configure a virtual server:
Click New on the right side of the Virtual Servers screen to open
1
the Virtual Server Settings dialogue box.
Enter the IP address of the computer in the Server IP Address text
2
box.
3 Select the Service from the pull-down list.
Figure 45 Virtual Servers Settings Screen
If you select Custom, the screen shown in
Specify a suitable name for the service and then enter the port
numbers required for that service. If a service requires more than
one port number enter the multiple ports as a comma separated
list or a range e.g. 51,52,54-59.
49
(Figure 45).
Figure 46 displays.