'\" t
.\"     Title: zmq_tcp
.\"    Author: [see the "AUTHORS" section]
.\" Generator: DocBook XSL Stylesheets v1.76.1 <http://docbook.sf.net/>
.\"      Date: 05/02/2013
.\"    Manual: 0MQ Manual
.\"    Source: 0MQ 3.2.2
.\"  Language: English
.\"
.TH "ZMQ_TCP" "7" "05/02/2013" "0MQ 3\&.2\&.2" "0MQ Manual"
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.SH "NAME"
zmq_tcp \- 0MQ unicast transport using TCP
.SH "SYNOPSIS"
.sp
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\&.
.SH "ADDRESSING"
.sp
A 0MQ endpoint is a string consisting of a \fItransport\fR:// followed by an \fIaddress\fR\&. The \fItransport\fR specifies the underlying protocol to use\&. The \fIaddress\fR specifies the transport\-specific address to connect to\&.
.sp
For the TCP transport, the transport is tcp, and the meaning of the \fIaddress\fR part is defined below\&.
.SS "Assigning a local address to a socket"
.sp
When assigning a local address to a socket using \fIzmq_bind()\fR with the \fItcp\fR transport, the \fIendpoint\fR shall be interpreted as an \fIinterface\fR followed by a colon and the TCP port number to use\&.
.sp
An \fIinterface\fR may be specified by either of the following:
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
The wild\-card
*, meaning all available interfaces\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
The primary IPv4 or IPv6 address assigned to the interface, in its numeric representation\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
The non\-portable interface name as defined by the operating system\&.
.RE
.sp
The TCP port number may be specified by:
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
A numeric value, usually above 1024 on POSIX systems\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
The wild\-card
*, meaning a system\-assigned ephemeral port\&.
.RE
.sp
When using ephemeral ports, the caller should retrieve the actual assigned port using the ZMQ_LAST_ENDPOINT socket option\&. See \fBzmq_getsockopt\fR(3) for details\&.
.SS "Connecting a socket"
.sp
When connecting a socket to a peer address using \fIzmq_connect()\fR with the \fItcp\fR transport, the \fIendpoint\fR shall be interpreted as a \fIpeer address\fR followed by a colon and the TCP port number to use\&.
.sp
A \fIpeer address\fR may be specified by either of the following:
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
The DNS name of the peer\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
The IPv4 or IPv6 address of the peer, in its numeric representation\&.
.RE
.SH "EXAMPLES"
.PP
\fBAssigning a local address to a socket\fR. 
.sp
.if n \{\
.RS 4
.\}
.nf
//  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);
.fi
.if n \{\
.RE
.\}
.PP
\fBConnecting a socket\fR. 
.sp
.if n \{\
.RS 4
.\}
.nf
//  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);
.fi
.if n \{\
.RE
.\}
.sp
.SH "SEE ALSO"
.sp
\fBzmq_bind\fR(3) \fBzmq_connect\fR(3) \fBzmq_pgm\fR(7) \fBzmq_ipc\fR(7) \fBzmq_inproc\fR(7) \fBzmq\fR(7)
.SH "AUTHORS"
.sp
This 0MQ manual page was written by Pieter Hintjens <\m[blue]\fBph@imatix\&.com\fR\m[]\&\s-2\u[1]\d\s+2>, Martin Sustrik <\m[blue]\fBsustrik@250bpm\&.com\fR\m[]\&\s-2\u[2]\d\s+2> and Martin Lucina <\m[blue]\fBmato@kotelna\&.sk\fR\m[]\&\s-2\u[3]\d\s+2>\&.
.SH "NOTES"
.IP " 1." 4
ph@imatix.com
.RS 4
\%mailto:ph@imatix.com
.RE
.IP " 2." 4
sustrik@250bpm.com
.RS 4
\%mailto:sustrik@250bpm.com
.RE
.IP " 3." 4
mato@kotelna.sk
.RS 4
\%mailto:mato@kotelna.sk
.RE