InformationEnable all Flood Protection options in the Zone Protection Profile attached to all untrusted zones. The Alert, Activate, and Maximum settings for Flood Protection depend highly on the environment and device used. Perform traffic analysis on the specific environment and firewall to determine accurate thresholds. Do not rely on default values to be appropriate for an environment.
Setting these values for all interfaces is an approach that should be considered by many organizations, as traffic floods can result from internal testing or malware as well.
Without flood protection, it may be possible for an attacker, through the use of a botnet or other means, to overwhelm network resources. Flood protection does not completely eliminate this risk; rather, it provides a layer of protection. Without a properly configured zone protection profile applied to untrusted interfaces, the protected / trusted networks are susceptible to large number of attacks. While many of these involve denial of service, some of these attacks are designed to evade IPS systems (fragmentation attacks for instance) or to evade basic firewall protections (source routing and record route attacks).
Not configuring and applying a Network Zone Protection Profile leaves an organization exposed to common attacks and reconnaissance from untrusted networks.
Not configuring a Zone Protection Profile for internal networks leaves an organization vulnerable to malware, software or hardware causes of traffic flooding from internal sources.
SolutionIn the GUI:
Navigate to Network > Network Profiles > Zone Protection > Flood Protection.
Set all settings to 'enabled' with at least the default values.
Navigate to Network > Zones, select each untrusted zone in turn, and set the Zone Protection Profile.