Справочник Пользователя для ZyXEL 660HW-D1 91-004-593010B

P-660H/HW-D Series User’s Guide

175

Chapter 10 Firewall Configuration

The ZyXEL Device also sends alerts whenever TCP Maximum Incomplete is exceeded. The 
global values specified for the threshold and timeout apply to all TCP connections. 

Click Firewall, and Threshold to bring up the next screen.

Figure 97   Firewall: Threshold

The following table describes the labels in this screen.

Table 63   Firewall: Threshold

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 ZyXEL Device continues to 

delete half-open sessions as necessary, until 

the rate of new connection attempts drops 

below this number.

80 existing half-open sessions.

One Minute High

This is the rate of new half-open sessions that 

causes the firewall to start deleting half-open 

sessions. When the rate of new connection 

attempts rises above this number, the ZyXEL 

Device deletes half-open sessions as 

required to accommodate new connection 

attempts.

100 half-open sessions per minute. 

The above numbers cause the 

ZyXEL Device to start deleting half-

open sessions when more than 

100 session establishment 

attempts have been detected in the 

last minute, and to stop deleting 

half-open sessions when fewer 

than 80 session establishment 

attempts have been detected in the 

last minute.