ZyXEL P-660HW-T1 v3 User Guide - Page 203

Configuring Firewall Thresholds

Page 203 highlights

Chapter 10 Firewalls 5 Type of traffic for certain servers. Reduce the threshold values if your network is slower than average for any of these factors (especially if you have servers that are slow or handle many tasks and are often busy). • If you often use P2P applications such as file sharing with eMule or eDonkey, it's recommended that you increase the threshold values since lots of sessions will be established during a small period of time and the ZyXEL Device may classify them as DoS attacks. 10.4.2 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 > Threshold to bring up the next screen. Figure 83 Security > Firewall > Threshold The following table describes the labels in this screen. Table 57 Security > Firewall > Threshold LABEL DESCRIPTION Denial of Service Thresholds The ZyXEL Device measures both the total number of existing halfopen sessions and the rate of session establishment attempts. Both TCP and UDP half-open sessions are counted in the total number and rate measurements. Measurements are made once a minute. One Minute Low This is the rate of new half-open sessions per minute 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. P-660HW-Tx v3 Series User's Guide 203

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Chapter 10 Firewalls
P-660HW-Tx v3 Series User’s Guide
203
5
Type of traffic for certain servers.
Reduce the threshold values if your network is slower than average for any of
these factors (especially if you have servers that are slow or handle many tasks
and are often busy).
If you often use P2P applications such as file sharing with eMule or eDonkey, it’s
recommended that you increase the threshold values since lots of sessions will
be established during a small period of time and the ZyXEL Device may classify
them as DoS attacks.
10.4.2
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
>
Threshold
to bring up the next screen.
Figure 83
Security > Firewall > Threshold
The following table describes the labels in this screen.
Table 57
Security > Firewall > Threshold
LABEL
DESCRIPTION
Denial of Service
Thresholds
The ZyXEL Device measures both the total number of existing half-
open sessions and the rate of session establishment attempts. Both
TCP and UDP half-open sessions are counted in the total number and
rate measurements. Measurements are made once a minute.
One Minute Low
This is the rate of new half-open sessions per minute 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.