User guide

SmartDefense Categories
Chapter 11: Using SmartDefense 225
Table 52: Small PMTU Fields
In this field… Do this…
Action
Specify what action to take when a packet is smaller than the Minimal MTU
Size threshold, by selecting one of the following:
• Block. Block the packet.
• None. No action. This is the default.
Track
Specify whether to issue logs for packets are smaller than the Minimal MTU
Size threshold, by selecting one of the following:
• Log. Issue logs. This is the default.
• None. Do not issue logs.
Minimal MTU
Size
Type the minimum value allowed for the MTU field in IP packets sent by a
client.
An overly small value will not prevent an attack, while an overly large value
might degrade performance and cause legitimate requests to be dropped.
The default value is 300.