zmq_tcp(7) - Linux man page
Name
zmq_tcp - 0MQ unicast transport using TCP
Synopsis
TCP is an ubiquitous, reliable, unicast transport. When connecting distributed applications over a network with 0MQ, using the TCP transport will likely be your first choice.
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 TCP transport, the transport is tcp, and the meaning of the address part is defined below.
Assigning a local address to a socket
- When assigning a local address to a socket using zmq_bind() with the tcp transport, the endpoint shall be interpreted as an
interface followed by a colon and the TCP port number to use.
An interface may be specified by either of the following:
- • The wild-card *, meaning all available interfaces.
- • The primary IPv4 or IPv6 address assigned to the interface, in its numeric representation.
- • The non-portable interface name as defined by the operating system.
- • The primary IPv4 or IPv6 address assigned to the interface, in its numeric representation.
- The TCP port number may be specified by:
- • A numeric value, usually above 1024 on POSIX systems.
- • The wild-card *, meaning a system-assigned ephemeral port.
- When using ephemeral ports, the caller should retrieve the actual assigned port using the ZMQ_LAST_ENDPOINT socket option. See zmq_getsockopt(3) for details.
Connecting a socket
- When connecting a socket to a peer address using zmq_connect() with the tcp transport, the endpoint shall be interpreted as a peer
address followed by a colon and the TCP port number to use.
A peer address may be specified by either of the following:
- • The DNS name of the peer.
- • The IPv4 or IPv6 address of the peer, in its numeric representation.
Examples
Assigning a local address to a socket.
-
// TCP port 5555 on all available interfaces rc = zmq_bind(socket, "tcp:/// :5555"); assert (rc == 0); // TCP port 5555 on the local loop-back interface on all platforms rc = zmq_bind(socket, "tcp://127.0.0.1:5555"); assert (rc == 0); // TCP port 5555 on the first Ethernet network interface on Linux rc = zmq_bind(socket, "tcp://eth0:5555"); assert (rc == 0);
- Connecting a socket.
-
// Connecting using an IP address rc = zmq_connect(socket, "tcp://192.168.1.1:5555"); assert (rc == 0); // Connecting using a DNS name rc = zmq_connect(socket, "tcp://server1:5555"); assert (rc == 0);
See Also
zmq_bind(3) zmq_connect(3) zmq_pgm(7) zmq_ipc(7) zmq_inproc(7) zmq(7)
Authors
This 0MQ manual page was written by Pieter Hintjens <ph@imatix.com [1] >, Martin Sustrik <sustrik@250bpm.com [2] > and Martin Lucina <mato@kotelna.sk [3] >.