.\" Copyright, the authors of the Linux man-pages project
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.TH IP_MULTICAST_LOOP 2const 2025-11-25 "Linux man-pages 6.17"
.SH NAME
IP_MULTICAST_LOOP
\-
loop back sent multicast packets to local sockets
.SH LIBRARY
Standard C library
.RI ( libc ,\~ \-lc )
.SH SYNOPSIS
.nf
.BR "#include <netinet/in.h>" "  /* Definition of " IP* " constants */"
.B #include <sys/socket.h>
.P
.BI int\~setsockopt(int\~ sockfd ,\~IPPROTO_IP,\~IP_MULTICAST_LOOP,
.BI "               const\~int\~*" enable ,\~sizeof(int));
.BI int\~getsockopt(int\~ sockfd ,\~IPPROTO_IP,\~IP_MULTICAST_LOOP,
.BI "               int\~*" enabled ,\~sizeof(int));
.fi
.SH DESCRIPTION
Set or read a boolean integer argument that determines whether
sent multicast packets should be looped back to the local sockets.
.SH ERRORS
See
.BR IPPROTO_IP (2const).
See
.BR setsockopt (2).
See
.BR ip (7).
.SH HISTORY
Linux 1.2.
.SH SEE ALSO
.BR IPPROTO_IP (2const),
.BR setsockopt (2),
.BR ip (7)