Chapter 3: Protecting Your Network
|
39
N300 Wireless Gigabit ADSL2+ Modem Router DGN3500 User Manual
Firewall Rules
Firewall rules block or allow specific traffic passing through from one side of the router to the
other. Inbound rules (WAN to LAN) restrict access by outsiders to private resources,
selectively allowing only specific outside users to access specific resources. Outbound rules
(LAN to WAN) determine what outside resources local users can have access to.
A firewall has two default rules, one for inbound traffic and one for outbound. The default
rules of the wireless modem router are:
•
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.
You can define additional rules that will specify exceptions to the default rules. By adding
custom rules, you can block or allow access based on the service or application, source or
destination IP addresses, and time of day. You can also choose to log traffic that matches or
does not match the rule you have defined.
You can change the order of precedence of rules so that the rule that applies most often
takes effect first. See
Order of Precedence for Rules
on page 44 for more details.
To access the rules configuration of the wireless modem router, select
Firewall Rules
on the
main menu, and then click
Add
for either an outbound or inbound service. The Firewall Rules
screen displays.
Figure 17.
•
To edit an existing rule, select its button on the left side of the table, and click
Edit
.
•
To delete an existing rule, select its button on the left side of the table, and click
Delete
.
•
To move an existing rule to a different position in the table, select its button on the left
side of the table, and click
Move
. At the prompt, enter the number of the desired new
position and click
OK
.
