anchor.diff:                  |> SsdpMessage.ToPacket
   
               let addrs = SsdpNetworkInterfaces.getSspdAddresses() |> Seq.cache
  -            let sockets = addrs |> Seq.map configUdp |> Seq.toList
  +            let sockets = addrs |> Seq.map (configUdp multicastLoopback) |> Seq.toList
               sockets |> List.iter (fun udp -> udp.Send(packet,
                                                         packet.Length,
                                                         SsdpConstants.SsdpEndPointIPv4)
  
positive.code:                 // No guarantee here; with a timeout some could starve, but at least there
                  // likely won't be many active network interfaces.
  
              return results.Length > 0
          }
  
  
negative.code:     /// Useful for debugging.
      member __.Name = name
  
      /// Request information from a service. Assumes you'll handle messages via an instance
      /// of SsdpClient.
      static member SendServiceQueryAsync (serviceType : string,
                                           userAgent : string,
                                           multicastLoopback : bool) : Task<bool> =
  
          async {
              let packet =
                  MSearch
                      {
                          Host        = SsdpConstants.SsdpEndPointIPv4
                          MAN         = "\"ssdp:discover\""
                          MX          = ""
                          ST          = serviceType
                          UserAgent   = userAgent
                      }
                  |> SsdpMessage.ToPacket
  
              let addrs = SsdpNetworkInterfaces.getSspdAddresses() |> Seq.cache
              let sockets = addrs |> Seq.map (configUdp multicastLoopback) |> Seq.toList
              sockets |> List.iter (fun udp -> udp.Send(packet,
                                                        packet.Length,
                                                        SsdpConstants.SsdpEndPointIPv4)
                                                    |> ignore
                                               udp.Close())
              return addrs |> Seq.length > 0
          }
          |> Async.StartAsTask
  
      /// Request information from a service. `onMessage` may be called on multiple
      /// threads concurrently.
      [<CompiledName("SearchFSharp")>]
  