ZyXEL Communications P-661H Series, User Manual, Page: 177 / 383

P-661H/HW Series User’s Guide
Chapter 9 Firewall Configuration 177
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
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.