Make client use the same webserver our landing page got when requesting authentication token

Attaching what we ended up doing with the F5 configuration for the remote service.

when HTTP_REQUEST {
  if { [class match [IP::client_addr] equals LP_IP]  } {
    pool RemoteApp
    persist none
  }
  else {
    if { [string tolower [HTTP::uri]] ends_with "/s_a" } {
      set uri [string map -nocase {"/s_a" ""} [HTTP::uri]]
      HTTP::uri $uri 
      pool RemoteApp member 99.99.99.98 80
    }
    elseif { [string tolower [HTTP::uri]] ends_with "/s_b" } {
      set uri [string map -nocase {"/s_b" ""} [HTTP::uri]]
      HTTP::uri $uri 
      pool RemoteApp member 99.99.99.99 80
    }        
    else { 
      pool RemoteApp 

    }
  }
}

when HTTP_RESPONSE {
  if { [class match [IP::client_addr] equals LP_IP ]  } {
    HTTP::header insert VIA [LB::server addr]
  }
}