Dos Thresholds; Threshold Values; Figure 131 Firewall Example: Rules: Myservice - ZyXEL Communications P-2602H User Manual

Figure 131 Firewall Example: Rules: MyService

15.8 DoS Thresholds

For DoS attacks, the ZyXEL Device uses thresholds to determine when to drop sessions that
do not become fully established. These thresholds apply globally to all sessions.
You can use the default threshold values, or you can change them to values more suitable to
your security requirements.
Refer to Section 15.8.3 on page 222

15.8.1 Threshold Values

Tune these parameters when something is not working and after you have checked the firewall
counters. These default values should work fine for most small offices. Factors influencing
choices for threshold values are:
• The maximum number of opened sessions.
• The minimum capacity of server backlog in your LAN network.
• The CPU power of servers in your LAN network.
• Network bandwidth.
• Type of traffic for certain servers.
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), then the default values should be
reduced.
You should make any changes to the threshold values before you continue configuring
firewall rules.
P-2602H(W)(L)-DxA User's Guide
Chapter 15 Firewall Configuration
to configure thresholds.
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