IP_MULTICAST_ALL(2const)                              IP_MULTICAST_ALL(2const)

NAME
       IP_MULTICAST_ALL - delivery policy of multicast messages

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <netinet/in.h>  /* Definition of IP* constants */
       #include <sys/socket.h>

       int setsockopt(int sockfd, IPPROTO_IP, IP_MULTICAST_ALL,
                      const int *val, sizeof(int));

DESCRIPTION
       This option can be used to modify the delivery policy of multicast
       messages.

       If set to 1 (default), the socket will receive messages from all the
       groups that have been joined globally on the whole system.

       If set to 0, it will deliver messages only from the groups that have
       been explicitly joined (for example via IP_ADD_MEMBERSHIP(2const)) on
       this particular socket.

ERRORS
       See IPPROTO_IP(2const).  See setsockopt(2).  See ip(7).

HISTORY
       Linux 2.6.31.

SEE ALSO
       IPPROTO_IP(2const), setsockopt(2), ip(7)

Linux man-pages 6.17              2025-11-25          IP_MULTICAST_ALL(2const)