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Chapter 10 Firewalls
P-660HN-F1A User’s Guide
190
• Use the Threshold screen (
) to set the thresholds that
the P-660HN-F1A uses to determine when to start dropping sessions that do not
become fully established (half-open sessions).
10.1.2 What You Need to Know About Firewall
DoS
Denials of Service (DoS) attacks are aimed at devices and networks with a
connection to the Internet. Their goal is not to steal information, but to disable a
device or network so users no longer have access to network resources. The
ZyXEL Device is pre-configured to automatically detect and thwart all known DoS
attacks.
Anti-Probing
If an outside user attempts to probe an unsupported port on your P-660HN-F1A,
an ICMP response packet is automatically returned. This allows the outside user to
know the P-660HN-F1A exists. The P-660HN-F1A supports anti-probing, which
prevents the ICMP response packet from being sent. This keeps outsiders from
discovering your P-660HN-F1A when unsupported ports are probed.
ICMP
Internet Control Message Protocol (ICMP) is a message control and error-reporting
protocol between a host server and a gateway to the Internet. ICMP uses Internet
Protocol (IP) datagrams, but the messages are processed by the TCP/IP software
and directly apparent to the application user.
DoS Thresholds
For DoS attacks, the P-660HN-F1A uses thresholds to determine when to drop
sessions that do not become fully established. These thresholds apply globally to
all sessions. You can use the default threshold values, or you can change them to
values more suitable to your security requirements.
Finding Out More
• See
for an example of setting up a firewall.
• See
for advanced technical information on firewall.
Содержание P-660HN-F1A
Страница 2: ......
Страница 10: ...Contents Overview P 660HN F1A User s Guide 10...
Страница 20: ...Table of Contents P 660HN F1A User s Guide 20...
Страница 21: ...21 PART I User s Guide...
Страница 22: ...22...
Страница 36: ...Chapter 2 Introducing the Web Configurator P 660HN F1A User s Guide 36...
Страница 44: ...Chapter 3 Status Screens P 660HN F1A User s Guide 44...
Страница 77: ...Chapter 4 Tutorials P 660HN F1A User s Guide 77 2 Leave the other settings as their defaults and click Apply...
Страница 84: ...Chapter 4 Tutorials P 660HN F1A User s Guide 84 Physical Port 1 3 exclude port 4 3 Click Apply...
Страница 88: ...Chapter 4 Tutorials P 660HN F1A User s Guide 88...
Страница 103: ...103 PART II Technical Reference...
Страница 104: ...104...
Страница 142: ...Chapter 7 LAN Setup P 660HN F1A User s Guide 142...
Страница 188: ...Chapter 9 Network Address Translation NAT P 660HN F1A User s Guide 188...
Страница 210: ...Chapter 10 Firewalls P 660HN F1A User s Guide 210...
Страница 236: ...Chapter 13 Certificates P 660HN F1A User s Guide 236...
Страница 240: ...Chapter 14 Static Route P 660HN F1A User s Guide 240...
Страница 256: ...Chapter 16 Quality of Service QoS P 660HN F1A User s Guide 256 Figure 111 QoS Class Example Boss 2...
Страница 276: ...Chapter 17 Dynamic DNS Setup P 660HN F1A User s Guide 276...
Страница 288: ...Chapter 18 Remote Management P 660HN F1A User s Guide 288...
Страница 344: ...Chapter 24 Troubleshooting P 660HN F1A User s Guide 344...
Страница 376: ...Appendix A Setting up Your Computer s IP Address P 660HN F1A User s Guide 376...
Страница 386: ...Appendix B Pop up Windows JavaScripts and Java Permissions P 660HN F1A User s Guide 386...
Страница 396: ...Appendix C IP Addresses and Subnetting P 660HN F1A User s Guide 396...
Страница 420: ...Appendix F Legal Information P 660HN F1A User s Guide 420...
Страница 430: ...Index P 660HN F1A User s Guide 430...