ip(7) Miscellaneous Information Manual ip(7) ip - IPv4 #include #include #include /* superset of previous */ tcp_socket = socket(AF_INET, SOCK_STREAM, 0); udp_socket = socket(AF_INET, SOCK_DGRAM, 0); raw_socket = socket(AF_INET, SOCK_RAW, protocol); 4 RFC 791 RFC 1122. ip 2 RFC 1112. IP . BSD-sockets. socket(7). IP socket(2): socket(AF_INET, socket_type, protocol); SOCK_STREAM SOCK_DGRAM SOCK_RAW raw(7) IP. protocol IP IP . protocol : o 0 IPPROTO_TCP tcp(7); o 0 IPPROTO_UDP udp(7); o IPPROTO_SCTP sctp(7); o IPPROTO_UDPLITE udplite(7). SOCK_RAW IANA IP RFC 1700 . bind(2). IP ( ) . INADDR_ANY . listen(2) INADDR_ANY. connect(2) INADDR_ANY. TCP SO_REUSEADDR. TCP . IP IP 16 . IP udp(7) tcp(7). .sin_port IP. sockaddr_in(3type). .sin_family AF_INET. 2.2 EINVAL . .sin_port . 1024 ( : ). ( : CAP_NET_BIND_SERVICE ) bind(2) . IPv4 tcp(7) udp(7). .sin_addr IP. .s_addr in_addr(3type) . in_addr(3type) INADDR_* ( INADDR_LOOPBACK) htonl(3) inet_aton(3), inet_addr(3), inet_makeaddr(3) ( gethostbyname(3)). IPv4 . . SO_BROADCAST. . . htons(3) . / . : INADDR_LOOPBACK (127.0.0.1) INADDR_ANY (0.0.0.0) INADDR_BROADCAST (255.255.255.255) INADDR_BROADCAST SO_BROADCAST . IP ( .255 255.255.255.0) . SO_BROADCAST . ( .0 255.255.255.0) "" . ( " .") Linux 5.14 . Linux . [0.0.0.1, 0.255.255.255] [240.0.0.0, 255.255.255.254] (0/8 240/4) . Linux 5.3 Linux 2.6.25 0/8 240/4 INADDR_ANY INADDR_BROADCAST . . [127.0.0.1, 127.255.255.254] (127/8) INADDR_LOOPBACK (127.0.0.1) [224.0.0.0, 239.255.255.255] (224/4) . IPPROTO_IP(2const). /proc proc_sys_net_ipv4(5). Ioctls ioctls socket(7) ip. ioctls netdevice(7). EACCES . : SO_BROADCAST prohibit ( CAP_NET_ADMIN) ( CAP_NET_BIND_SERVICE). EADDRINUSE . EADDRNOTAVAIL . EAGAIN . EALREADY . ECONNABORTED accept(2). EHOSTUNREACH . ICMP . EINVAL . blackhole. EISCONN connect(2) . EMSGSIZE MTU . ENOBUFS ENOMEM . 100%. ENOENT SIOCGSTAMP . ENOPKG . ENOPROTOOPT EOPNOTSUPP . ENOTCONN . EPERM . EPIPE . ESOCKTNOSUPPORT . tcp(7) raw(7) udp(7) socket(7). SO_BROADCAST - . . . . RFC 6762 (mDNS) . SOL_IP BSD IPPROTO_IP. INADDR_ANY (0.0.0.0) INADDR_BROADCAST (255.255.255.255) . htonl(3) . 2.0 socket(AF_INET, SOCK_PACKET, protocol) packet(7). socket(AF_PACKET, SOCK_RAW, protocol) . sockaddr_ll sockaddr_pkt . . (connect(2) bind(2) listen(2) sendto(2)) . ioctl IP ARP . MSG_ERRQUEUE msg_name recvmsg(2) 2.2. IPPROTO_IP(2const) recvmsg(2) sendmsg(2) byteorder(3) capabilities(7) icmp(7) ipv6(7) netdevice(7) netlink(7) raw(7) socket(7) tcp(7) udp(7) ip(8) Documentation/networking/ip-sysctl.rst. RFC 791 IP . RFC 1122 IPv4. RFC 1812 IPv4. 3 . . : . 6.18 8 2026 ip(7)