Chapter 10 Firewalls
P-660HWP-Dx User’s Guide
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• Always shred confidential information, particularly about your computer, before throwing
it away. Some hackers dig through the trash of companies or individuals for information
that might help them in an attack.
10.7 Packet Filtering Vs Firewall
Below are some comparisons between the P-660HWP-Dx’s filtering and firewall functions.
10.7.1 Packet Filtering:
• The router filters packets as they pass through the router’s interface according to the filter
rules you designed.
• Packet filtering is a powerful tool, yet can be complex to configure and maintain,
especially if you need a chain of rules to filter a service.
• Packet filtering only checks the header portion of an IP packet.
10.7.1.1 When To Use Filtering
• To block/allow LAN packets by their MAC addresses.
• To block/allow special IP packets which are neither TCP nor UDP, nor ICMP packets.
• To block/allow both inbound (WAN to LAN) and outbound (LAN to WAN) traffic
between the specific inside host/network "A" and outside host/network "B". If the filter
blocks the traffic from A to B, it also blocks the traffic from B to A. Filters can not
distinguish traffic originating from an inside host or an outside host by IP address.
• To block/allow IP trace route.
10.7.2 Firewall
• The firewall inspects packet contents as well as their source and destination addresses.
Firewalls of this type employ an inspection module, applicable to all protocols, that
understands data in the packet is intended for other layers, from the network layer (IP
headers) up to the application layer.
• The firewall performs stateful inspection. It takes into account the state of connections it
handles so that, for example, a legitimate incoming packet can be matched with the
outbound request for that packet and allowed in. Conversely, an incoming packet
masquerading as a response to a nonexistent outbound request can be blocked.
• The firewall uses session filtering, i.e., smart rules, that enhance the filtering process and
control the network session rather than control individual packets in a session.
• The firewall provides e-mail service to notify you of routine reports and when alerts occur.
10.7.2.1 When To Use The Firewall
• To prevent DoS attacks and prevent hackers cracking your network.
• A range of source and destination IP addresses as well as port numbers can be specified
within one firewall rule making the firewall a better choice when complex rules are
required.
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 ...