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Cisco Intrusion Prevention System Sensor CLI Configuration Guide for IPS 7.2
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Appendix B Signature Engines
Meta Engine
Tabl e B-13 lists the parameters specific to the Flood Ho st engine.
Flood Net Engine Parameters
Tabl e B-14 lists the parameters specific to the Flood Net engine.
For More Information
For more information on the parameters common to all signature engines, see Master Engine, page B-4.
Meta Engine
Caution
A large number of Meta engine signatures could adversely affect overall sensor performa nce.
The Meta engine defines events that occur in a related manner within a sliding time interval. This engine
processes events rather than packets. As signature events are generated, the Meta engine inspects them
to determine if they match any or several Meta definitions. The Meta engine generates a signature event
after all requirements for the event are met.
TableB-13 Flood Host Engine Parameters
Parameter Description Value
protocol Specifies which kind of traffic to inspect. ICMP
UDP
rate Specifies the threshold number of packets per second. 0 to 65535
1
1. An alert fires when the rate is greater than the packets per second.
icmp-type Specifies the value for the ICMP header type. 0 to 65535
dst-ports Specifies the destination ports when you choose UDP proto col. 0 to 65535
2
a-b[,c-d]
2. The second number in the range must be greater than or equal to the first number.
src-ports Specifies the source ports when you choose UDP protocol. 0 to 65535
2
a-b[,c-d]
TableB-14 Flood Net Engine Parameters
Parameter Description Value
gap Specifies the gap of time allowed (in s econds) for a flood
signature.
0 to 65535
peaks Specifies the number of allowed peaks of flood traffic. 0 to 65535
protocol Specifies which kind of traffic to inspect. ICMP
TCP
UDP
rate Specifies the threshold number of packets per second. 0 to 65535
1
1. An alert fires when the rate is greater than the packets per second.
sampling-interval Specifies the interval used for sampling traffic. 1 to 3600
icmp-type Specifies the value for the ICMP header type. 0 to 65535