H3C Technologies H3C S3100 Series Switches - Manual (Page 400)

4-1
4
System-Guard Configuration (For S3100-EI)
The configuration introduced in this chapter is only supported by the S3100-EI series switches.
System-Guard Overview
At first, you must determine whether the CPU is under attack to implement system guard for the CPU.
You should not determine whether the CPU is under attack just according to whether congestion occurs
in a queue. Instead, you must do that in the following ways:
z According to the number of packets processed in the CPU in a time range.
z Or according to the time for one hundred packets to be processed.
If the CPU is under attack, the rate of packets to be processed in the CPU in a certain queue will exceed
the threshold value. In this case, you can determine that the CPU is under attack. Through analyzing
these packets , you get to know the characteristics of the attack source, and then you can adopt
different filtering rules according the characteristics of the attack source. Thus, system guard is
implemented.
Configuring the System-Guard Feature
Through the following configuration, you can enable the system-guard feature, set the threshold for the
number of packets when an attack is detected and the length of the isolation after an attack is detected.
Configuring the System-Guard Feature
Table 4-1 Configure the system-guard feature
Operation Command Description
Enter system view system-view —
Enable the system-guard
feature
system-guard enable
Required
By default, the system-guard
feature is disabled.
Enable system-guard on
specified ports system-guard permit
interface-list
Required
By default, the system-guard
function is disabled on a port.
Set the threshold for the
number of packets when an
attack is detected system-guard
detect-threshold
threshold-value Optional
The default threshold value is 200
packets.