P-2608HWL-Dx Series User’s Guide
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Chapter 15 Firewalls
15.7.1.1 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.
15.7.2 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.
15.7.2.1 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.
• To selectively block/allow inbound or outbound traffic between inside host/networks and
outside host/networks. Remember that filters can not distinguish traffic originating from
an inside host or an outside host by IP address.
• The firewall performs better than filtering if you need to check many rules.
• Use the firewall if you need routine e-mail reports about your system or need to be alerted
when attacks occur.
• The firewall can block specific URL traffic that might occur in the future. The URL can
be saved in an Access Control List (ACL) database.
Содержание P-2608HWL-D1
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Страница 7: ...P 2608HWL Dx Series User s Guide Safety Warnings 7 This product is recyclable Dispose of it properly ...
Страница 24: ...P 2608HWL Dx Series User s Guide 24 Table of Contents ...
Страница 32: ...P 2608HWL Dx Series User s Guide 32 List of Figures ...
Страница 38: ...P 2608HWL Dx Series User s Guide 38 List of Tables ...
Страница 44: ...P 2608HWL Dx Series User s Guide 44 Chapter 1 Getting To Know the ZyXEL Device ...
Страница 66: ...P 2608HWL Dx Series User s Guide 66 Chapter 3 Internet and Wireless Setup Wizard ...
Страница 72: ...P 2608HWL Dx Series User s Guide 72 Chapter 4 VoIP Wizard And Example ...
Страница 78: ...P 2608HWL Dx Series User s Guide 78 Chapter 5 Bandwidth Management Wizard ...
Страница 88: ...P 2608HWL Dx Series User s Guide 88 Chapter 6 Status Screens ...
Страница 118: ...P 2608HWL Dx Series User s Guide 118 Chapter 8 LAN Setup ...
Страница 138: ...P 2608HWL Dx Series User s Guide 138 Chapter 9 Wireless LAN ...
Страница 166: ...P 2608HWL Dx Series User s Guide 166 Chapter 11 SIP ...
Страница 176: ...P 2608HWL Dx Series User s Guide 176 Chapter 12 Phone ...
Страница 184: ...P 2608HWL Dx Series User s Guide 184 Chapter 13 Phone Book ...
Страница 206: ...P 2608HWL Dx Series User s Guide 206 Chapter 16 Firewall Configuration Figure 107 Firewall Edit Rule ...
Страница 220: ...P 2608HWL Dx Series User s Guide 220 Chapter 17 Content Filtering ...
Страница 257: ...P 2608HWL Dx Series User s Guide Chapter 19 Certificates 257 Figure 138 My Certificate Details ...
Страница 268: ...P 2608HWL Dx Series User s Guide 268 Chapter 19 Certificates Figure 146 Trusted Remote Host Details ...
Страница 276: ...P 2608HWL Dx Series User s Guide 276 Chapter 20 Static Route ...
Страница 288: ...P 2608HWL Dx Series User s Guide 288 Chapter 21 Bandwidth Management ...
Страница 292: ...P 2608HWL Dx Series User s Guide 292 Chapter 22 Dynamic DNS Setup ...
Страница 306: ...P 2608HWL Dx Series User s Guide 306 Chapter 23 Remote Management Configuration ...
Страница 318: ...P 2608HWL Dx Series User s Guide 318 Chapter 24 Universal Plug and Play UPnP ...
Страница 324: ...P 2608HWL Dx Series User s Guide 324 Chapter 25 System ...
Страница 344: ...P 2608HWL Dx Series User s Guide 344 Chapter 27 Tools ...
Страница 348: ...P 2608HWL Dx Series User s Guide 348 Chapter 28 Diagnostic ...
Страница 360: ...P 2608HWL Dx Series User s Guide 360 Chapter 29 Troubleshooting ...
Страница 378: ...P 2608HWL Dx Series User s Guide 378 Appendix B Setting up Your Computer s IP Address ...
Страница 402: ...P 2608HWL Dx Series User s Guide 402 Appendix F Triangle Route ...
Страница 440: ...P 2608HWL Dx Series User s Guide 440 Appendix H Internal SPTGEN ...