Security Settings
50
N600 Wireless Dual Band Gigabit ADSL2+ Modem Router DGND3700
To specify a trusted computer:
1.
In the
Trusted IP Address
field, enter the IP address.
2.
Click
Apply
to save your changes.
Firewall Rules to Control Network Access
By default your router blocks any inbound traffic from the Internet to your computers except
for replies to your outbound traffic. You might need to create exceptions to this rule to allow
remote computers to access a server on your local network or to allow certain applications
and games to work correctly. Your router provides port forwarding and port triggering for
creating these exceptions.
This section covers the following topics:
• Remote Computer Access Basics
• Port Triggering to Open Incoming Ports
• Port Forwarding to Permit External Host Communications
• How Port Forwarding Differs from Port Triggering
• Configure Port Forwarding to Local Servers
• Configure Port Triggering
Remote Computer Access Basics
When a computer on your network needs to access a computer on the Internet, your
computer sends your router a message containing the source and destination address and
process information. Before forwarding your message to the remote computer, your router
has to modify the source information and create and track the communication session so that
replies can be routed back to your computer.
Here is an example of normal outbound traffic and the resulting inbound responses:
1.
You open a browser and your operating system assigns port number 5678 to this
browser session.
2.
You type http://www.example.com into the URL field, and your computer creates a web page
request message with the following address and port information. The request message is
sent to your router.
Source address
. Your computer’s IP address.
Source port number
. 5678, which is the browser session.
Destination address
. The IP address of www.example.com, which your computer finds
by asking a DNS server.
Destination port number
. 80, which is the standard port number for a web server
process.
