ZyWALL 70 User’s Guide
Chapter 10 Firewall Screens
199
Whenever the number of half-open sessions with the same destination host address rises above
a threshold (
TCP Maximum Incomplete
), the ZyWALL starts deleting half-open sessions
according to one of the following methods:
1
If the
Blocking Time
timeout is 0 (the default), then the ZyWALL deletes the oldest
existing half-open session for the host for every new connection request to the host. This
ensures that the number of half-open sessions to a given host will never exceed the
threshold.
2
If the
Blocking Time
timeout is greater than 0, then the ZyWALL blocks all new
connection requests to the host giving the server time to handle the present connections.
The ZyWALL continues to block all new connection requests until the
Blocking Time
expires.
The ZyWALL also sends alerts whenever
TCP Maximum Incomplete
is exceeded. The
global values specified for the threshold and timeout apply to all TCP connections. Click the
FIREWALL
link and then the
Threshold
tab to bring up the next screen.
Figure 79
Firewall Threshold
The following table describes the labels in this screen.
Table 61
Firewall Threshold
LABEL
DESCRIPTION
Denial of Service
Thresholds
One Minute Low
This is the rate of new half-open sessions that causes the firewall to stop deleting
half-open sessions. The ZyWALL continues to delete half-open sessions as
necessary, until the rate of new connection attempts drops below this number.
Содержание ZyWALL 70
Страница 1: ...ZyWALL 70 Internet Security Appliance User s Guide Version 3 64 3 2005 ...
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Страница 38: ...ZyWALL 70 User s Guide 38 List of Figures ...
Страница 46: ...ZyWALL 70 User s Guide 46 List of Tables ...
Страница 74: ...ZyWALL 70 User s Guide 74 Chapter 2 Introducing the Web Configurator ...
Страница 92: ...ZyWALL 70 User s Guide 92 Chapter 3 Wizard Setup ...
Страница 102: ...ZyWALL 70 User s Guide 102 Chapter 4 LAN Screens ...
Страница 108: ...ZyWALL 70 User s Guide 108 Chapter 5 Bridge Screens ...
Страница 130: ...ZyWALL 70 User s Guide 130 Chapter 6 Wireless LAN ...
Страница 136: ...ZyWALL 70 User s Guide 136 Chapter 7 WAN Screens Figure 45 WAN General ...
Страница 155: ...ZyWALL 70 User s Guide Chapter 7 WAN Screens 155 Figure 55 Dial Backup Setup ...
Страница 188: ...ZyWALL 70 User s Guide 188 Chapter 10 Firewall Screens Figure 71 Creating Editing A Firewall Rule ...
Страница 193: ...ZyWALL 70 User s Guide Chapter 10 Firewall Screens 193 Figure 76 My Service Rule Configuration ...
Страница 234: ...ZyWALL 70 User s Guide 234 Chapter 13 Introduction to IPSec ...
Страница 246: ...ZyWALL 70 User s Guide 246 Chapter 14 VPN Screens Figure 112 VPN Rules IKE Gateway Policy Edit ...
Страница 252: ...ZyWALL 70 User s Guide 252 Chapter 14 VPN Screens Figure 113 VPN Rules IKE Network Policy Edit ...
Страница 275: ...ZyWALL 70 User s Guide Chapter 15 Certificates 275 Figure 125 My Certificate Details ...
Страница 294: ...ZyWALL 70 User s Guide 294 Chapter 16 Authentication Server Figure 136 Local User Database ...
Страница 314: ...ZyWALL 70 User s Guide 314 Chapter 17 Network Address Translation NAT ...
Страница 318: ...ZyWALL 70 User s Guide 318 Chapter 18 Static Route ...
Страница 324: ...ZyWALL 70 User s Guide 324 Chapter 19 Policy Route ...
Страница 340: ...ZyWALL 70 User s Guide 340 Chapter 20 Bandwidth Management ...
Страница 376: ...ZyWALL 70 User s Guide 376 Chapter 22 Remote Management ...
Страница 390: ...ZyWALL 70 User s Guide 390 Chapter 24 Logs Screens Figure 194 Log Settings ...
Страница 413: ...ZyWALL 70 User s Guide Chapter 25 Maintenance 413 Figure 216 Restart Screen ...
Страница 414: ...ZyWALL 70 User s Guide 414 Chapter 25 Maintenance ...
Страница 440: ...ZyWALL 70 User s Guide 440 Chapter 28 WAN and Dial Backup Setup ...
Страница 456: ...ZyWALL 70 User s Guide 456 Chapter 31 DMZ Setup ...
Страница 460: ...ZyWALL 70 User s Guide 460 Chapter 32 Route Setup ...
Страница 470: ...ZyWALL 70 User s Guide 470 Chapter 33 Remote Node Setup ...
Страница 522: ...ZyWALL 70 User s Guide 522 Chapter 39 System Information Diagnosis ...
Страница 538: ...ZyWALL 70 User s Guide 538 Chapter 40 Firmware and Configuration File Maintenance ...
Страница 550: ...ZyWALL 70 User s Guide 550 Chapter 42 Remote Management ...
Страница 558: ...ZyWALL 70 User s Guide 558 Chapter 43 IP Policy Routing ...
Страница 573: ...ZyWALL 70 User s Guide Chapter 45 Troubleshooting 573 Figure 360 Java Sun ...
Страница 574: ...ZyWALL 70 User s Guide 574 Chapter 45 Troubleshooting ...
Страница 582: ...ZyWALL 70 User s Guide 582 Appendix B Removing and Installing a Fuse ...
Страница 602: ...ZyWALL 70 User s Guide 602 Appendix D IP Subnetting ...
Страница 608: ...ZyWALL 70 User s Guide 608 Appendix F PPTP ...
Страница 626: ...ZyWALL 70 User s Guide 626 Appendix H Triangle Route ...
Страница 656: ...ZyWALL 70 User s Guide 656 Appendix K Importing Certificates ...
Страница 658: ...ZyWALL 70 User s Guide 658 Appendix L Command Interpreter ...
Страница 664: ...ZyWALL 70 User s Guide 664 Appendix M Firewall Commands ...
Страница 668: ...ZyWALL 70 User s Guide 668 Appendix N NetBIOS Filter Commands ...
Страница 674: ...ZyWALL 70 User s Guide 674 Appendix P Brute Force Password Guessing Protection ...
Страница 696: ...ZyWALL 70 User s Guide 696 Appendix R Log Descriptions ...