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Cisco Intrusion Prevention System Sensor CLI Configuration Guide for IPS 7.2
OL-29168-01
Chapter9 Co nfiguring Anomaly Detection
Configuring the Illegal Zone
Configuring the Illegal Zone
This section describes how to configure the illegal zone, and contains the following topics:
Understanding the Illegal Zone, page 9-20
Configuring the Illegal Zone, page 9-20
Configuring TCP Protocol for the Illegal Zone, page 9-21
Configuring UDP Protocol for the Illegal Zone, page 9-24
Configuring Other Protocols for the Illegal Zone, page 9-26

Understanding the Illegal Zone

The illegal zone should represent IP address ranges that should never be seen in normal traffic, for
example, unallocated IP addresses or part of your internal IP address r ange that is unoccupied. You then
add the IP addresses that belong to this zone. If you do not configure IP addresses for all zones, all
packets are sent to the default zone, the external zone.
You can enable or disable TCP, UDP, and other protocols for the internal zone. You can configure a
destination port for the TCP and UDP protocols and a protocol number for the other protocols. You can
either use the default thresholds or override the scanner settings and add your own thresholds and
histograms.

Configuring the Illegal Zone

Use the illegal-zone {enabled | ip-address-range | tcp | udp |other} command in service anomaly
detection submode to enable the illegal zone, add IP addresses to the illegal zone, and specify protocols.
The following options apply:
enabled {false | true}—Enables/disables the zone.
ip-address-range—Specifies the IP addresses of the subnets in the zone. The valid value is
<A.B.C.D>-<A.B.C.D>[,<A.B.C.D>-<A.B.C.D>].
Note
The second IP address in the range must be greater than or equal to the first IP address.
tcp—Lets you configure TCP protocol.
udp—Lets you configure UDP protocol.
other—Lets you configure other protocols besides TCP and UDP.
Configuring the Illegal Zone
To configure the illegal zone, follow these steps:
Step 1
Log in to the CLI using an account with administrator privileges.
Step 2
Enter anomaly detection illegal zone submode.
sensor# configure terminal
sensor(config)# service anomaly-detection ad0
sensor(config-ano)# illegal-zone