Laboratory Eleven – Firewall
You have to disable the proxy, by
Objective: clicking option, connection and LAN
setting
1) To test firewall
Procedure1
The objective is to install a firewall to test the protection. A
firewall is used to secure your personal information by taking
preventative measures against hackers and viruses. Firewalls
software offer frontline protection against unauthorized access
to your system or data. The typical concept of a firewall only
blocking inbound network traffic by having the product
monitoring and blocking outbound traffic. In this laboratory,
you will test one firewall and two firewall test tools (test the
security of firewall.)
Do it At home, you can try a few mores: Norton Internet Security 2002,
at (Triware) , http://www.symantec.com, BlackICE Defender for
home workstation (shareware) www.networkice.com, Lockdown Millenium
(shareware) www.lockdowncorp.com
The firewall we are going to test is a shareware called Privatefirewall software. Now
download it from http://www.privatefirewall.com
Now click privatefirewall ,
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run the file privatefirewall.exe, you will see the following screen.
Now click yes, you will have the following screen:
Now reboot the software. Remember to use CTRL-K when you choose the XP
System.
Use
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Firewall on:
means filter
out traffic
Now click application, you will see the screen
Procedure 1: set the outgoing traffic
Start the Internet Explorer and access my web site:
http://personal.cityu.edu.hk/~dcykcho/
Now click the Internet Explorer below from the screen of Privatefirewall :
You will see a screen like this:
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In the above screen, you could modify the rules. Currently, all the traffics are free to
travel over the Internet. Now, modify the Primary HTTP Connec . Highlight it and
click modify. Change to deny as follows.
Press Okay. (You are now changing the rule
to deny any outgoing traffic. Direction of rule)
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Now switch to Internet Explorer and type in the web site, http://www.altavista.com
You will find that it displays an application detection as follows:
Since you block the traffic, you could not access the www.altavista.com. The system
will display an error like this.
Please note that you have just configured a firewall to block all outgoing traffic.
Procedure 2: Reset the outgoing traffic
Now change the setting to allow by clicking the screen below:
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now access the www.download.com, www.cityu.edu.hk or http://www.altavista.com ,
you will find that it will not display the screen asking your action.
Now change the setting to allow outgoing traffic only as follows:
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Click http://www.altavista.com, you will find that the firewall will block all incoming
traffic.
Up to here, you know how to block and allow traffic.
one mark____________
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Procedure 3: Change the port number to disable traffic through Web
The HTTP protocol that the Explorer used is based on the port number 80. If you
modify this port number, it will affect your access to the outgoing traffic. Now the
setting is as follows:
Now access www.altavista.com, you will see that the firewall has blocked
incoming/outgoing traffic with port number 80 as follows:
However, it will not block the traffic using FTP. Now invoke FTP and performs a
normal connection as follows:
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enter {student id} followed by {password}.
Up to here, you understand that we just configured the firewall to disable all traffic
through the Web (port 80), but we still allow traffic to form connection through the
FTP service.
Procedure 4: Change the configuration to disable traffic through FTP, but to
enable traffic through IE Explorer
Now modify the application menu to resume normal as follows:
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And configure the FTP application to disable the traffic.
Configure the setting as follows:
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The screen will be as follows showing that the traffic is disabled:
now access http://www.hku.hk, it will display as follows
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which means that your firewall allows http,
now click the DOS prompt and type ftp as shown below, you will find that the traffic
is blocked.
You can either modify the rule or change the setting to on
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You can then connect it
After you
changed to
firewall off
finally, click the firewall log to see the activity.
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One mark ________
Remark: If you still have time, please play around other applications.
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