code: private static int joinMcGroupsOnAllNetworkInterfaces(MulticastSocket pSocket, InetSocketAddress pSocketAddress, LogHandler pLogHandler) throws IOException {
          // V6: ffx8::/16
          Enumeration<NetworkInterface> nifs = NetworkInterface.getNetworkInterfaces();
          int interfacesJoined = 0;
          while (nifs.hasMoreElements()) {
              NetworkInterface n = nifs.nextElement();
              if (NetworkUtil.isMulticastSupported(n)) {
                  try {
                      pSocket.joinGroup(pSocketAddress, n);
                      interfacesJoined++;
                  } catch (IOException exp) {
                      pLogHandler.info("Cannot join multicast group on NIF " + n.getDisplayName() + ": " + exp.getMessage());
                  }
              }
          }
          return interfacesJoined;
      }
docs: We are using all interfaces available and try to join them