ZyXEL Communications P-3202HN-Ba User Manual page 152

Chapter 12 Firewalls
Type of traffic for certain servers.
5
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 IAD may classify them as
DoS attacks.
12.4.2 Configuring Firewall Thresholds
The IAD 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 70 Security > Firewall > Threshold
The following table describes the labels in this screen.
Table 48 Security > Firewall > Threshold
LABEL
Denial of Service
Thresholds
One Minute Low
152
DESCRIPTION
The IAD 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.
This is the rate of new half-open sessions per minute that causes the
firewall to stop deleting half-open sessions. The IAD continues to
delete half-open sessions as necessary, until the rate of new
connection attempts drops below this number.
IAD User's Guide