Packets sent to node-local scoped addresses escape out on the network

iflocal.c

#include <sys/socket.h>
#include <netinet/ip6.h>
#include <string.h>

int main(int argc, char *argv[])
{
	int s;
	struct sockaddr_in6 si_iflocal = {0};
	const char *msg = "hello";
	s=socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
	si_iflocal.sin6_family = AF_INET6;
	si_iflocal.sin6_port = htons(51000);
	inet_pton(AF_INET6, "ff01::1", &si_iflocal.sin6_addr);
	sendto(s, msg, strlen(msg), 0, (struct sockaddr *) &si_iflocal, sizeof(si_iflocal));
	close(s);
	return 0;
}