How do I determine the user-agent for traffic?

Products

• ProxySG Software - SGOS

Issue/Introduction

There are a few websites available that provides a list of user-agents (sucyh as http://www.user-agents.org). However, the best way to determine the user-agent a certain traffic uses is by taking a packet capture. It is recommended to perform the capture on the client initiating the request. You can take a packet capture with a protocol analyzer (such as Wireshark or Ethereal) or using the ProxySG itself (see KB2995).

Once you have the packet capture, you can filter on only the HTTP requests (specify the http.request filter). The following is an example of an HTTP request to www.google.com.my:

 

After you locate the session in the list of filtered HTTP requests, you can determine the user-agent by looking at the HTTP request header.

In the above filter, the user-agent for this particular session is:

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.8) Gecko/20100722 Firefox/3.6.8 ( .NET CLR 3.5.30729)