Summary

This document contains information about using the Rewrite feature of the NetScaler appliance to change the destination path of a GET request based on the User-Agent.

Requirements

Before you start configuring the Rewrite feature, it is advisable to record an HTTP Header trace to confirm the User-Agents for the client requests. The following are the sample User-Agents that connected the Web site by using the Firefox version 3.5.8 and Microsoft Internet Explorer version 7.0:

Firefox User-Agent:

User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.8) Gecko/20100202 Firefox/3.5.8 GTB6 (.NET CLR 3.5.30729)

Internet Explorer User-Agent:

User-Agent: Mozilla/4.0 (compatible; GoogleToolbar 6.4.1321.1732; Windows XP 5.1; MSIE 7.0.5730.11)

You can configure the rewrite policy to match any expression in the User-Agent header value field.

Using the Rewrite Feature of the NetScaler Appliance to Change the Destination Path of a GET Request Based on the User-Agent

To use the Rewrite feature of the NetScaler appliance to change the destination path of a GET request based on the User-Agent, complete the following procedure from the command line interface of the appliance:

Run the following command to create a Rewrite action to insert Firefox after the HTTP request URL:

add rewrite action ua_rewrite_Firefox_act insert_after HTTP.REQ.URL "\"Firefox\""

Run the following command to create a Rewrite action to insert IE after the HTTP request URL:

add rewrite action ua_rewrite_IE_act insert_after HTTP.REQ.URL "\"IE\""

Run the following command to create a policy to match User-Agent header for Firefox and ignore case in the request URL:

add rewrite policy ua_rewrite_Firefox_pol "http.REQ.HEADER(\"User-Agent\").SET_TEXT_MODE(IGNORECASE).REGEX_MATCH(re/Firefox/) " ua_rewrite_Firefox_act

Run the following command to create a policy to match User-Agent header for Internet Explorer and ignore case in the request URL:

add rewrite policy ua_rewrite_IE_pol "http.REQ.HEADER(\"User-Agent\").SET_TEXT_MODE(IGNORECASE).REGEX_MATCH(re/MSIE/) " ua_rewrite_IE_act

Run the following command to bind the policies you created to the required Load Balancing virtual server:

bind lb vserver ua_redirect_LB -policyName ua_rewrite_Firefox_pol -priority 100 -gotoPriorityExpression END -type REQUEST
bind lb vserver ua_redirect_LB -policyName ua_rewrite_IE_pol -priority 110 -gotoPriorityExpression END -type REQUEST

More Information

The following screenshot displays the traces of the packets recorded to show a GET request from a Firefox client to the / directory being directed to the /Firefox directory for the NetScaler appliance request to the backend server. Additionally, a GET request from an Internet Explorer client to the / directory is directed to the /IE directory for the NetScaler appliance request to the backend server.