URL filtering provides visibility and control over web traffic
on your network. For improved visibility into web content, you can
configure the URL Filtering profile to log HTTP header attributes
included in a web request. When a client requests a web page, the
HTTP header includes the user agent, referer, and x-forwarded-for fields
as attribute-value pairs and forwards them to the web server. When
enabled for logging HTTP headers, the firewall logs the following
attribute-value pairs in the URL Filtering logs.