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Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter44 Configuring Inspection for Voice and Video Protocols
SIP Inspection
Where the regex regex_na me argument is the regular expression you created in Step1. The class
regex_class_name is the regular expression class map you created in Step2.
h. (Optional) To match a SIP via header, enter the following command:
hostname(config-cmap)# match [not] message-path regex {class class_name | regex_name}
Where the regex regex_na me argument is the regular expression you created in Step1. The class
regex_class_name is the regular expression class map you created in Step2.
i. (Optional) To match a SIP request method, enter the following command:
hostname(config-cmap)# match [not] request-method method
Where method is the type of method to match (ack, bye, cancel, info, invite, message, notify,
options, prack, refer, register, subscribe, unknown, update).
j. (Optional) To match the requester of a third-party registration, enter the following command:
hostname(config-cmap)# match [not] third-party-registration regex {class class_name |
regex_name}
Where the regex regex_na me argument is the regular expression you created in Step1. The class
regex_class_name is the regular expression class map you created in Step2.
k. (Optional) To match an URI in the SIP headers, enter the following command:
hostname(config-cmap)# match [not] uri {sip | tel} length gt length
Where length is the number of bytes the URI is greater than. 0 to 65536.
Step4 Create a SIP inspection policy map, enter the following command:
hostname(config)# policy-map type inspect sip policy_map_name
hostname(config-pmap)#
Where the policy_map_name is the name of the policy map. The CLI enters policy-map configuration
mode.
Step5 (Optional) To add a description to the policy map, enter the following command:
hostname(config-pmap)# description string
Step6 To apply actions to matching traffic, perform the following steps.
a. Specify the traffic on which you want to perform actions using one of the following methods:
•Specify the SIP class map that you created in Step3 by entering the following command:
hostname(config-pmap)# class class_map_name
hostname(config-pmap-c)#
•Specify traffic directly in the policy map using one of the match commands described in Step3.
If you use a match not command, then any traffic that does not match the criterion in the match
not command has the action applied.
b. Specify the action you want to perform on the matching traffic by entering the following command:
hostname(config-pmap-c)# {[drop [send-protocol-error] |
drop-connection [send-protocol-error]| mask | reset] [log] | rate-limit message_rate}
Not all options are available for each match or class command. See the CLI help or the command
reference for the exact options available.
The drop keyword drops all packets that match.
The send-protocol-error keyword sends a protocol error message.