P-661H/HW Series User’s Guide

9.11.3 Configuring Firewall Thresholds

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 67 Firewall: Threshold

LABEL

DESCRIPTION

DEFAULT VALUES

 

 

 

Denial of Service

 

 

Thresholds

 

 

One Minute Low

This is the rate of new half-open sessions that

80 existing half-open sessions.

 

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.

 

One Minute High

This is the rate of new half-open sessions that

100 half-open sessions per minute.

 

causes the firewall to start deleting half-open

The above numbers cause the

 

sessions. When the rate of new connection

ZyXEL Device to start deleting half-

 

attempts rises above this number, the ZyXEL

open sessions when more than

 

Device deletes half-open sessions as

100 session establishment

 

required to accommodate new connection

attempts have been detected in the

 

attempts.

last minute, and to stop deleting

 

 

half-open sessions when fewer

 

 

than 80 session establishment

 

 

attempts have been detected in the

 

 

last minute.

Chapter 9 Firewall Configuration

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