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Cisco Intrusion Prevention System Sensor CLI Configuration Guide for IPS 7.2
OL-29168-01
Chapter7 Defining Signatures
Creating Custom Signatures
Step 10
Specify the regex string to search for in the TCP packet. You can change the event actions if needed
according to your security policy using the event-action command. The default event action is
produce-alert.
sensor(config-sig-sig-str)# regex-string This-is-my-new-Sig-regex
Step 11
You can modify the following optional parameters for this custom String TCP signature:
specify-exact-match-offset
specify-min-match-length
strip-telnet-options
swap-attacker-victim.
Step 12
Verify the settings.
sensor(config-sig-sig-str)# show settings
string-tcp
-----------------------------------------------
event-action: produce-alert <defaulted>
strip-telnet-options: false <defaulted>
specify-min-match-length
-----------------------------------------------
no
-----------------------------------------------
-----------------------------------------------
-----------------------------------------------
regex-string: This-is-my-new-Sig-regex
service-ports: 23
direction: to-service default: to-service
specify-exact-match-offset
-----------------------------------------------
no
-----------------------------------------------
specify-max-match-offset
-----------------------------------------------
no
-----------------------------------------------
-----------------------------------------------
-----------------------------------------------
specify-min-match-offset
-----------------------------------------------
no
-----------------------------------------------
-----------------------------------------------
-----------------------------------------------
-----------------------------------------------
-----------------------------------------------
swap-attacker-victim: false <defaulted>
-----------------------------------------------
sensor(config-sig-sig-str)#
Step 13
Exit signature definition submode.
sensor(config-sig-sig-str)# exit
sensor(config-sig-sig)# exit
sensor(config-sig)# exit
Apply Changes:?[yes]:
Step 14
Press Enter to apply the changes or enter
no
to discard them.