IP_MULTICAST_IF fails #990
Description
On rs_preview build 14905:
The following works on Linux, but fails in WSL:
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <err.h>
#include <errno.h>
#include <stdio.h>
int main(void)
{
printf("Creating socket\n");
int s = socket(AF_INET, SOCK_DGRAM, 0);
if (s < 0)
err(1, "%d", errno);
ip_mreqn opt = { .imr_multiaddr = { .s_addr = 0 },
.imr_address = { .s_addr = 0 },
.imr_ifindex = 0 };
if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF, &opt, sizeof(opt)) != 0)
err(1, "%d", errno);
printf("Success!\n");
return 0;
}.NET Core has support for setting the multicast interface by either address or interface index, so this impacts .NET Core functionality.