Netgear DM111PSPv2 – ADSL2+ Ethernet Modem User Manual
Security Settings
29
Broadband ADSL2+ Modem DM111PSPv2
Specify a Trusted Computer
You can exempt one trusted computer from blocking and logging. That computer has to be
configured to use a a fixed IP address.
configured to use a a fixed IP address.
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 firewall rules for creating these exceptions.
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 firewall rules for creating these exceptions.
Authorized communications are established according to inbound and outbound rules. The
firewall has the following two default rules. You can create custom rules to further restrict the
outbound communications or more widely open the inbound communications:
firewall has the following two default rules. You can create custom rules to further restrict the
outbound communications or more widely open the inbound communications:
•
Inbound. Block all access from outside except responses to requests from the LAN side.
•
Outbound. Allow all access from the LAN side to the outside.
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.
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.
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.
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.
by asking a DNS server.
Destination port number. 80, which is the standard port number for a web server
process.
process.