External to internal Redirect broken

Create a server pool internal_pool with ip_address_of_internal.company.com:40000 as the pool member and then use the following irule:

when HTTP_REQUEST {
if { [string tolower [HTTP::host]] equals "external.company.com" } {
    switch -glob [string tolower [HTTP::uri]] {
        "/dev" {
            pool internal_pool
        }
      }
   }
}