IPV6_MULTICAST

The API uses IPV6_MULTICAST_LOOP socket option to enable or disable the loopback of outgoing multicast datagrams. The default is enabled. This option is used to enable an application with multiple senders and receivers on a system to loop datagrams back so that each process receives the transmissions of the other senders on the system. Figure 1 illustrates the use of IPV6_MULTICAST_LOOP by the use of the SETSOCKOPT and GETSOCKOPT APIs.

Figure 1. IPV6_MULTICAST_LOOP

          ***********************************************************************
          *                                                                     *
          *        Issue SETSOCKOPT/GETSOCKOPT - IPV6_MULTICAST_LOOP ENABLED    *
          *                                                                     *
          ***********************************************************************
                   EZASMI TYPE=SETSOCKOPT,  ISSUE SETSOCKOPT                     X
                         S=S,               SOCKET DESCRIPTOR                    X
                         OPTLEN=OPTLEN1,    OPTION LENGTH                        X
                         OPTNAME='IPV6_MULTICAST_LOOP', OPTION NAME              X
                         OPTVAL=OPTVALON,   OPTION VALUE                         X
                         RETCODE=RETCODE,   (SPECIFY RETCODE FIELD)              X
                         ERROR=ERROR        ABEND IF MACRO ERROR  
                   BAL   R14,RCCHECK         --> CHECK IT             
          *
                   XC    OPTVAL4,OPTVAL4                             
                   EZASMI TYPE=GETSOCKOPT,  ISSUE GETSOCKOPT                     X
                         S=S,               SOCKET DESCRIPTOR                    X
                         OPTLEN=OPTLEN1,    OPTION LENGTH                        X
                         OPTNAME='IPV6_MULTICAST_LOOP', OPTION NAME              X
                         OPTVAL=OPTVAL4,    OPTION VALUE                         X
                         RETCODE=RETCODE,   (SPECIFY RETCODE FIELD)              X
                         ERROR=ERROR        ABEND IF MACRO ERROR      
                   BAL   R14,RCCHECK         --> CHECK IT

         ***********************************************************************
         *                                                                     *
         *        Issue SETSOCKOPT/GETSOCKOPT - IPV6_MULTICAST_LOOP DISABLED   *
         *                                                                     *
         ***********************************************************************
                  EZASMI TYPE=SETSOCKOPT,  ISSUE SETSOCKOPT                     X
                        S=S,               SOCKET DESCRIPTOR                    X
                        OPTLEN=OPTLEN1,    OPTION LENGTH                        X
                        OPTNAME='IPV6_MULTICAST_LOOP', OPTION NAME              X
                        OPTVAL=OPTVALOFF,  OPTION VALUE                         X
                        RETCODE=RETCODE,   (SPECIFY RETCODE FIELD)              X
                        ERROR=ERROR        ABEND IF MACRO ERROR     
                  BAL   R14,RCCHECK         --> CHECK IT               
                     :
                     :
                  XC    OPTVAL4,OPTVAL4                    
                  EZASMI TYPE=GETSOCKOPT,  ISSUE GETSOCKOPT                     X
                        S=S,               SOCKET DESCRIPTOR                    X
                        OPTLEN=OPTLEN1,    OPTION LENGTH                        X 
                        OPTNAME='IPV6_MULTICAST_LOOP', OPTION NAME              X 
                        OPTVAL=OPTVAL4,    OPTION VALUE                         X
                        RETCODE=RETCODE,   (SPECIFY RETCODE FIELD)              X
                        ERROR=ERROR        ABEND IF MACRO ERROR    
                  BAL   R14,RCCHECK         --> CHECK IT