opt = 1;
setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
(void *)&opt, sizeof opt);
opt = 1;
setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
(void *)&opt, sizeof opt);
opt = 0;
setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY,
(void *)&opt, sizeof opt);
opt = 0;
setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY,
(void *)&opt, sizeof opt);