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Cisco Intrusion Prevention System Sensor CLI Configuration Guide for IPS 7.2
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Chapter8 Configuring Event Action Rules
Event Action Variables
Understanding Event Action Variables
Note
Global correlation inspection and the reputation filtering deny features do not supp ort IPv6 addresses.
For global correlation inspection, the sensor does not receive or process reputation data for IPv6
addresses. The risk rating for IPv6 addresses is not modified for global co rrelation inspection. Similarly,
network participation does not include event data for attacks from IPv6 addresses. And finally, IPv6
addresses do not appear in the deny list.
Note
Rate limiting and blocking are not supported for IPv6 traffic. If a signature is configured with a block or
rate limit event action and is triggered by IPv6 traffic, an alert is generated but the action is not carried
out.
You can create event variables and then use those variables in event action filters. When you want to use
the same value within multiple filters, use a variable. When you change the value of the variable, any
filter that uses that variable is updated with the new value.
Note
You must preface the event variable with a dollar ($) sign to indicate that you are using a variable rather
than a string.
Some variables cannot be deleted because they are necessa ry to the signature system. If a variable is
protected, you cannot select it to edit it. You receive an error message if you try to delete protected
variables. You can edit only one variable at a time.
IPv4 Addresses
When configuring IPv4 addresses, specify the full IP address or ranges or set of range s:
192.0.2.3-192.0.2.26
10.90.1.1
192.56.10.1-192.56.10.255
10.1.1.1-10.2.255.255, 192.0.2.3-192.0.2.26
IPv6 Addresses
When configuring IPv6 addresses, use the following format:
<XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX>-<XXXX:XXXX:XXXX:XXXX:XX
XX:XXXX:XXXX:XXXX>[,<XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX>-<XXX
X:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX>]
Note
IPv6 addresses are 128 bits represented in hexadecimal and divided into eight 16-bit groups
separated by colons. You can skip the leading zeros and you can represent the zeroed groups in
the middle with a double colon (::). You must start the address with the 2001:db8 prefix.