ZyXEL Communications 802.11g Wireless ADSL2+ 4-port VoIP IAD P-2602HWNLI - Manual (Page 229)

P-2602HWNLI User’s Guide
Chapter 14 Firewall Configuration 229
• If the Blocking Time timeout is 0 (the default), then the ZyXEL Device 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.
• If the Blocking Time timeout is greater than 0, then the ZyXEL Device blocks all new
connection requests to the host giving the server time to handle the present connections.
The ZyXEL Device continues to block all new connection requests until the Blocking
Time expires.
14.10.3 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 Security > Firewall > Threshold to bring up the next screen.
Figure 122 Firewall: Threshold
The following table describes the labels in this screen.
Table 81 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 ZyXEL Device continues to delete half-open sessions as
necessary, until the rate of new connection attempts drops below this number.