Cisco 5505 - ASA Firewall Edition Bundle, Cli Configuration Manual

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Cisco ASA Series CLI Configuration Guide
Chapter 1 Configuring Inspection of Basic Internet Protocols
HTTP Inspection
The send-protocol-error keyword sends a protocol error message.
The drop-connection keyword drops the packet and closes the connection.
The mask keyword masks out the matching portion of the packet.
The reset keyword drops the packet, closes the connection, and sends a TCP reset to the server
and/or client.
The log keyword, which you can use alone or with one of the other keywords, sends a system log
message.
The rate-limit message_rate argument limits the rate of messages.
You can specify multiple class or match commands in the policy map. For information about the order
of class and match commands, see the “Defining Actions in an Inspection Policy Map” section on
page 1-4 .
Step 7
To configure parameters that affect the inspection engine, perform the following steps:
a.
To enter parameters configuration mode, enter the following command:
hostname(config-pmap)#
parameters
hostname(config-pmap-p)#
b.
To check for HTTP protocol violations, enter the following command:
hostname(config-pmap-p)# protocol-violation [ action [ drop-connection | reset | log ]]
Where the drop-connection action closes the connection. The reset action closes the connection
and sends a TCP reset to the client. The log action sends a system log message when this policy map
matches traffic.
c.
To substitute a string for the server header field, enter the following command:
hostname(config-pmap-p)# spoof-server string
Where the string argument is the string to substitute for the server header field. Note: WebVPN
streams are not subject to the spoof-server comand.
The following example shows how to define an HTTP inspection policy map that will allow and log any
HTTP connection that attempts to access “www\.xyz.com/.*\.asp" or "www\.xyz[0-9][0-9]\.com" with
methods "GET" or "PUT." All other URL/Method combinations will be silently allowed.
hostname(config)#
regex url1 “www\.xyz.com/.*\.asp”
hostname(config)# regex url2 “www\.xyz[0-9][0-9]\.com”
hostname(config)# regex get “GET”
hostname(config)#
regex put “PUT”
hostname(config)# class-map type regex match-any url_to_log
hostname(config-cmap)#
match regex url1
hostname(config-cmap)# match regex url2
hostname(config-cmap)# exit
hostname(config)# class-map type regex match-any methods_to_log
hostname(config-cmap)# match regex get
hostname(config-cmap)#
match regex put
hostname(config-cmap)# exit
hostname(config)#
class-map type inspect http http_url_policy
hostname(config-cmap)# match request uri regex class url_to_log
hostname(config-cmap)# match request method regex class methods_to_log
hostname(config-cmap)#
exit