Carrier Access Adit 3200, Reference Manual

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Adit 3000 (Rel. 1.6) and MSR Card (Rel 2.0) GUI 4-13
Security
Local Servers
Local Servers
By default, the Adit blocks all external users from connecting to or communicating with your network.
Therefore the system is safe from hackers who may try to intrude on the network and damage it.
However, you may need to expose your network to the Internet in certain limited and controlled ways
to enable some applications to work from the LAN and to establish servers in the network. The Local
Servers feature supports both of these functions. If you are familiar with networking terminology and
concepts, you may have encountered this topic referred to as Port Forwarding.
The Local Servers tab on the Security window provides access to a list of the most commonly used
applications that require handling by the Adit. All you have to do is identify which of them you want
to use and the local IP address of the computer that will be using the service. For example, if you want
to use the Net2Phone voice application on one of your PCs, simply select Net2Phone from the list and
enter the local IP address of that computer in the
Local Host field. All Net2Phone-related data arriving
at the Adit from the Internet will be forwarded to the specified computer.
Similarly, if you want to grant Internet users access to servers inside your network, you must identify
each service that you want to provide and the PC that will provide it. For example, if you want to host
a Web server inside the network, select
HTTP - Web Server from the list and enter the local IP address
of the computer that will host the Web server in the Local Host field. Then, when a an Internet user
points the browser to the external IP address of the Adit, the Gateway will forward the incoming HTTP
request to the computer that is hosting the Web server.
Local Servers is a NAPT function. It only applies to packets whose destination address is the Adit's own
WAN IP address. When a local server match is applied, packets are redirected from the Adit WAN IP
address to the local server's IP address. Note that the Local Servers are active if either the firewall is
enabled on the WAN interface or the WAN interface routing type is set for NAPT.