beautypg.com

Enabling nids attack prevention signatures, Setting signature threshold values – Fortinet FortiGate 100 User Manual

Page 226

background image

226

Fortinet Inc.

Enabling NIDS attack prevention signatures

Network Intrusion Detection System (NIDS)

Enabling NIDS attack prevention signatures

The NIDS Prevention module contains signatures that are designed to protect your
network against attacks. Some signatures are enabled by default; others must be
enabled. For a complete list of NIDS Prevention signatures and descriptions, see the
FortiGate NIDS Guide.

1

Go to NIDS > Prevention.

2

Check the box in the Enable column beside each signature that you want to enable.

3

Select Check All

to enable all signatures in the NIDS attack prevention signature

list.

4

Select Uncheck All

to disable all signatures in the NIDS attack prevention

signature list.

5

Select Reset to Default Values

to enable only the default NIDS attack prevention

signatures and return to the default threshold values.

Figure 36: Example NIDS attack prevention signature list entries

Setting signature threshold values

You can change the default threshold values for the NIDS Prevention signatures listed
in

Table 6

. The threshold depends on the type of attack. For flooding attacks, the

threshold is the maximum number of packets received per second. For overflow
attacks, the threshold is the buffer size for the command. For large ICMP attacks, the
threshold is the ICMP packet size limit to pass through.