= zmq_udp(7) == NAME zmq_udp - 0MQ UDP multicast and unicast transport == SYNOPSIS UDP is unreliable protocol transport of data over IP networks. UDP support both unicast and multicast communication. == DESCRIPTION UDP transport can only be used with the 'ZMQ_RADIO' and 'ZMQ_DISH' socket types. == ADDRESSING A 0MQ endpoint is a string consisting of a 'transport'`://` followed by an 'address'. The 'transport' specifies the underlying protocol to use. The 'address' specifies the transport-specific address to connect to. For the UDP transport, the transport is `udp`. The meaning of the 'address' part is defined below. Binding a socket ---------------- With 'udp' we can only bind the 'ZMQ_DISH' socket type. When binding a socket using _zmq_bind()_ with the 'udp' transport the 'endpoint' shall be interpreted as an 'interface' followed by a colon and the UDP port number to use. An 'interface' may be specified by either of the following: * The wild-card `*`, meaning all available interfaces. * The name of the network interface (i.e. eth0, lo, wlan0 etc...) * The primary address assigned to the interface, in its numeric representation. * Multicast address in its numeric representation the socket should join. The UDP port number may be specified a numeric value, usually above 1024 on POSIX systems. Connecting a socket ------------------- With 'udp' we can only connect the 'ZMQ_RADIO' socket type. When connecting a socket to a peer address using _zmq_connect()_ with the 'udp' transport, the 'endpoint' shall be interpreted as a 'peer address' followed by a colon and the UDP port number to use. A 'peer address' may be specified by either of the following: * The IPv4 or IPv6 address of the peer, in its numeric representation or using its hostname. * Multicast address in its numeric representation. == EXAMPLES .Binding a socket ---- // Unicast - UDP port 5555 on all available interfaces rc = zmq_bind(dish, "udp://*:5555"); assert (rc == 0); // Unicast - UDP port 5555 on the local loop-back interface rc = zmq_bind(dish, "udp://127.0.0.1:5555"); assert (rc == 0); // Unicast - UDP port 5555 on interface eth1 rc = zmq_bind(dish, "udp://eth1:5555"); assert (rc == 0); // Multicast - UDP port 5555 on a Multicast address rc = zmq_bind(dish, "udp://239.0.0.1:5555"); assert (rc == 0); // Same as above but joining only on interface eth0 rc = zmq_bind(dish, "udp://eth0;239.0.0.1:5555"); assert (rc == 0); // Same as above using IPv6 multicast rc = zmq_bind(dish, "udp://eth0;[ff02::1]:5555"); assert (rc == 0); ---- .Connecting a socket ---- // Connecting using an Unicast IP address rc = zmq_connect(radio, "udp://192.168.1.1:5555"); assert (rc == 0); // Connecting using a Multicast address rc = zmq_connect(socket, "udp://239.0.0.1:5555); assert (rc == 0); // Connecting using a Multicast address using local interface wlan0 rc = zmq_connect(socket, "udp://wlan0;239.0.0.1:5555); assert (rc == 0); // Connecting to IPv6 multicast rc = zmq_connect(socket, "udp://[ff02::1]:5555); assert (rc == 0); ---- == SEE ALSO * xref:zmq_connect.adoc[zmq_connect] * xref:zmq_setsockopt.adoc[zmq_setsockopt] * xref:zmq_tcp.adoc[zmq_tcp] * xref:zmq_ipc.adoc[zmq_ipc] * xref:zmq_inproc.adoc[zmq_inproc] * xref:zmq_vmci.adoc[zmq_vmci] * xref:zmq.adoc[zmq] == AUTHORS This page was written by the 0MQ community. To make a change please read the 0MQ Contribution Policy at .