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Cisco Intrusion Prevention System Sensor CLI Configuration Guide for IPS 7.2
OL-29168-01
AppendixB Signature Engines
Service Engines
Tabl e B-19 lists the parameters that are specific to the Service FTP engine.
For More Information
For more information on the parameters common to all signature engines, see Master Engine, page B-4.
Service Generic Engine
The Service Generic engine allows programmatic signatures to be issued in a config-file-only signature
update. It has a simple machine and assembly language that is defined in the configuration file. It runs
the machine code (distilled from the assembly language) through its virtual machine, which processes
the instructions and pulls the important pieces of information out of the packet and runs them through
the comparisons and operations specified in the machine code. It is intended as a rapid signature
response engine to supplement the String and State engines.
New functionality adds the Regex parameter to the Service Generic engine a nd enhanced instructions.
The Service Generic engine can analyze traffic based on the mini-programs that are written to parse the
packets. These mini-programs are composed of commands, which dissect the packet and look for certain
conditions.
Note
You cannot use the Service Generic engine to create custom signatures.
Caution
Due to the proprietary nature of this complex language, we do not recommend that you edit the Service
Generic engine signature parameters other than severity and event action.
TableB-19 Service FTP Engine Parameters
Parameter Description Value
direction Specifies the direction of traffic:
Traffic from service port destined to client port.
Traffic from client port destined to service port.
from-service
to-service
ftp-inspection-type Specifies the type of inspection to perform:
Looks for an invalid address in the FTP port
command.
Looks for an invalid port in the FTP port
command.
Looks for the PASV port spoof.
bad-port-cmd-address
bad-port-cmd-port
pasv
service-ports Specifies a comma-separated list of ports or port
ranges where the target service resides.
0 to 65535
1
a-b[,c-d]
1. The second number in the range must be greater than or equal to the first number.
swap-attacker-victim Swaps the attacker and victim addresses and ports
(source and destination) in the alert message and in any
actions taken.
true | false (default)