Chapter 11 Firewall Configuration
P-660HWP-Dx User’s Guide
48
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If you configure firewall rules without a good understanding of how they work,
you might inadvertently introduce security risks to the firewall and to the
protected network. Make sure you test your rules after you configure them.
For example, you may create rules to:
• Block certain types of traffic, such as IRC (Internet Relay Chat), from the LAN to the
Internet.
• Allow certain types of traffic, such as Lotus Notes database synchronization, from specific
hosts on the Internet to specific hosts on the LAN.
• Allow everyone except your competitors to access a Web server.
• Restrict use of certain protocols, such as Telnet, to authorized users on the LAN.
These custom rules work by comparing the Source IP address, Destination IP address and IP
protocol type of network traffic to rules set by the administrator. Your customized rules take
precedence and override the P-660HWP-Dx’s default rules.
11.3 Rule Logic Overview
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Study these points carefully before configuring rules.
11.3.1 Rule Checklist
State the intent of the rule. For example, “This restricts all IRC access from the LAN to the
Internet.” Or, “This allows a remote Lotus Notes server to synchronize over the Internet to an
inside Notes server.”
1
Is the intent of the rule to forward or block traffic?
2
What direction of traffic does the rule apply to?
3
What IP services will be affected?
4
What computers on the LAN are to be affected (if any)?
5
What computers on the Internet will be affected? The more specific, the better. For
example, if traffic is being allowed from the Internet to the LAN, it is better to allow
only certain machines on the Internet to access the LAN.
11.3.2 Security Ramifications
1
Once the logic of the rule has been defined, it is critical to consider the security
ramifications created by the rule:
2
Does this rule stop LAN users from accessing critical resources on the Internet? For
example, if IRC is blocked, are there users that require this service?
Summary of Contents for 802.11g HomePlug AV ADSL2+ Gateway P-660HWP-Dx
Page 2: ......
Page 7: ...Safety Warnings P 660HWP Dx User s Guide 39 ...
Page 8: ...Safety Warnings P 660HWP Dx User s Guide 40 ...
Page 10: ...Contents Overview P 660HWP Dx User s Guide 36 ...
Page 20: ...Table of Contents P 660HWP Dx User s Guide 44 ...
Page 32: ...List of Tables P 660HWP Dx User s Guide 40 ...
Page 33: ...35 PART I Introduction Introducing the P 660HWP Dx 35 Introducing the Web Configurator 43 ...
Page 34: ...36 ...
Page 42: ...Chapter 1 Introducing the P 660HWP Dx P 660HWP Dx User s Guide 42 ...
Page 56: ...Chapter 2 Introducing the Web Configurator P 660HWP Dx User s Guide 48 ...
Page 58: ...36 ...
Page 78: ...Chapter 4 Bandwidth Management Wizard P 660HWP Dx User s Guide 54 ...
Page 80: ...36 ...
Page 98: ...Chapter 5 WAN Setup P 660HWP Dx User s Guide 52 ...
Page 142: ...Chapter 8 Powerline P 660HWP Dx User s Guide 42 ...
Page 156: ...36 ...
Page 176: ...Chapter 11 Firewall Configuration P 660HWP Dx User s Guide 54 Figure 99 Firewall Edit Rule ...
Page 190: ...Chapter 11 Firewall Configuration P 660HWP Dx User s Guide 68 ...
Page 194: ...Chapter 12 Content Filtering P 660HWP Dx User s Guide 72 ...
Page 218: ...36 ...
Page 222: ...Chapter 14 Static Route P 660HWP Dx User s Guide 38 ...
Page 238: ...Chapter 16 Dynamic DNS Setup P 660HWP Dx User s Guide 38 ...
Page 250: ...Chapter 17 Remote Management Configuration P 660HWP Dx User s Guide 46 ...
Page 262: ...Chapter 18 Universal Plug and Play UPnP P 660HWP Dx User s Guide 58 ...
Page 264: ...36 ...
Page 270: ...Chapter 19 System P 660HWP Dx User s Guide 40 ...
Page 288: ...Chapter 20 Logs P 660HWP Dx User s Guide 52 ...
Page 294: ...Chapter 21 Tools P 660HWP Dx User s Guide 40 ...
Page 304: ...36 ...
Page 340: ...Appendix C Internal SPTGEN P 660HWP Dx User s Guide 50 ...
Page 364: ...Appendix E IP Subnetting P 660HWP Dx User s Guide 42 ...
Page 368: ...Appendix F Command Interpreter P 660HWP Dx User s Guide 38 ...
Page 388: ...Appendix K Legal Information P 660HWP Dx User s Guide 38 ...
Page 394: ...Appendix L Customer Support P 660HWP Dx User s Guide 40 ...
Page 402: ...Index P 660HWP Dx User s Guide 42 ...