46

5

5.

Security

Keeping unwanted content out of your network

This chapter explains how to use the basic firewall features of the router to prevent objectionable

content from reaching the computers and devices on your network.

This chapter includes the following sections:

•

Keyword Blocking of HTTP Traffic

•

Block Services (Port Filtering)

•

Schedule Blocking

•

Security Event Email Notifications

Security

47

N150 4-Port Wireless Router JNR1010

Keyword Blocking of HTTP Traffic

Use keyword blocking to prevent certain types of HTTP traffic from accessing your network.

The blocking can be always or according to a schedule.

1.

Select

Advanced > Security >

Block Sites

to display the following screen:

2.

Select one of the keyword blocking options:

•

Per Schedule

. Turn on keyword blocking according to the Schedule screen settings.

•

Always

. Turn on keyword blocking all the time, independent of the Schedule screen.

3.

In the Keyword field, enter a keyword or domain, click

Add Keyword,

and click

Apply

.

The Keyword list supports up to 32 entries. Following are sample entries:

•

Specify XXX to block http://www.badstuff.com/xxx.html.

•

Specify .com if you want to allow only sites with domain suffixes such as .edu or .gov.

•

Enter a period (

.

) to block all Internet browsing access.



To delete a keyword or domain:

1.

Select the keyword you want to delete from the list.

2.

Click

Delete Keyword

and

Apply

to save your changes.



To specify a trusted computer:

You can exempt one trusted computer from blocking and logging. The computer you exempt

must have a fixed IP address.

1.

In the Trusted IP Address field, enter the IP address.

2.

Click

Apply

to save your changes.

Security

48

N150 4-Port Wireless Router JNR1010

Block Services (Port Filtering)

Services are functions that server computers perform at the request of client computers. For

example, web servers serve web pages, time servers serve time and date information, and

game hosts serve data about other players’ moves. When a computer on the Internet sends a

request for service to a server computer, the requested service is identified by a service or

port number. This number appears as the destination port number in the transmitted IP

packets. For example, a packet that is sent with the destination port number 80 is an HTTP

(web server) request.

The service numbers for many common protocols are defined by the Internet Engineering

Task Force (IETF at

) and published in RFC1700, “Assigned Numbers.”

Service numbers for other applications are typically chosen from the range 1024 to 65535 by

the authors of the application. Although the router already holds a list of many service port

numbers, you are not limited to these choices. You can often determine port number

information by contacting the publisher of the application, by asking user groups or

newsgroups, or by searching.

The Block Services screen lets you add and block specific Internet services by computers on

your network. This feature is called service blocking or port filtering. To add a service for

blocking, first determine which port number or range of numbers the application uses.



To block services:

1.

Select

Advanced > Security > Block Services

to display the following screen:

2.

Select either

Per Schedule

or

Always

to enable service blocking, and click

Apply

.

If you selected Per Schedule, specify a time period in the Schedule screen as described

in

Schedule Blocking

on page

50.

Security

49

N150 4-Port Wireless Router JNR1010

3.

Click

Add

to add a service.

The Block Services Setup screen displays:

4.

From the Service Type list, select the application or service to allow or block.

The list already displays several common services, but you are not limited to these

choices. To add any additional services or applications that do not already appear, select

User Defined.

5.

If you know that the application uses either TCP or UDP, select the appropriate protocol.

If you are not sure, select

Both

.

6.

Enter the starting and ending port numbers.

If the application uses a single port number, enter that number in both fields.

7.

Select the radio button for the IP address configuration you want to block and enter the IP

addresses.

You can block the specified service for a single computer, a range of computers with

consecutive IP addresses, or all computers on your network.

8.

Click

Add

to enable your Block Services Setup selections.

Security

50

N150 4-Port Wireless Router JNR1010

Schedule Blocking

You can specify the days and time that you want to block Internet access.



To schedule blocking:

1.

Select

Advanced > Security > Schedule

to display the following screen:

2.

Set up the schedule for blocking keywords and services.

•

Days to Block

. Select days on which you want to apply blocking by selecting the

appropriate check boxes, or select

Every Day

to select the check boxes for all days.

•

Time of Day to Block

. Select a start and end time in 24-hour format, or select

All

Day

for 24-hour blocking.

3.

Select your time zone from the list.

4.

If you use daylight savings time, select the

Automatically adjust for daylight savings time

check box.

5.

Click

Apply

to save your settings.