UTT Technologies Chapter 11 Firewall
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Page 181
11.2 Access Control
This section describes the
Firewall > Access Control
page, which includes the
Access
Rule List
and
Access Rule Settings
.
11.2.1 Introduction to Access Control
11.2.1.1 The Purpose of Access Control Feature
By flexibly utilizing access control, you can not only assign different Internet access
privileges to different LAN users, but also assign different Internet access privileges to the
same users based on schedules. In practice, you can set appropriate access rules
according to the actual requirements of your organization. Such as, for a school, you can
block the students from accessing game websites; for a family, you can only allow your
children to access the Internet during the specified period of time; for a business, you can
block the Financial Department
’s employees from accessing the Internet.
11.2.1.2 The Operation Principle of Access Control
By default, the Router will forward all the valid packets received by the LAN interface
because no access rule exists. After you have configured some access rules, the Router
will examine each packet received by the LAN interface to determine whether to forward
or drop it, based on the criteria you specified in the access rules.
More specifically, when receiving a packet initiated from LAN, the Router will analyze the
packet by extracting its source MAC address, source IP address, destination IP address,
protocol type, port number, content, and the date and time at which the packet was
received, and then compare them with each rule in decreasing order of priority. The first
rule that matches the packet is applied, and the specified
Action
(
Allow
or
Deny
) is taken.
After a match is found, no further rules are checked. Note that the rules are listed in
decreasing order of priority in the
Access Rule List
:
The rule with a higher priority is listed
before the one with a lower priority.
