Configure X-forwarded-for on WebSphere App server

From what I understand of Solr, it's a Java-based application that you install in a WebSphere or Tomcat environment. That essentially means it's HTTP-based, by virtue of the web engine, and has the ability to consume HTTP headers. We can certainly tell you how to get an HTTP header to the web server, but you're going to need to search Solr documentation on how to consume HTTP headers.