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<!DOCTYPE html><html lang="en"><head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width"> <title>UDP/Datagram Sockets | Node.js v12.10.0 Documentation</title> <link rel="stylesheet" href="data:text/css;base64,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"> <link rel="stylesheet" href="data:text/css;base64,/*--------------------- Layout and Typography ----------------------------*/
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em code {
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#gtoc {
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li.version-picker {
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li.version-picker:hover > a {
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tt, code {
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a code {
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#column2 > ul:nth-child(2) {
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#intro a:hover, #intro a:focus,
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th > *:last-child, td > *:last-child {
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.changelog > summary {
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/* simpler clearfix */
.clearfix:after {
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.github_icon {
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@media only screen and (max-width: 1024px) {
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@media print {
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"> <link rel="stylesheet" href="data:text/css;base64,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"> <link rel="canonical" href="https://nodejs.org/api/dgram.html"> </head> <body class="alt apidoc" id="api-section-dgram"> <div id="content" class="clearfix"> <div id="column2" class="interior"> <div id="intro" class="interior"> <a href="https://nodejs.org/" title="Go back to the home page"> Node.js </a> </div> <ul> <li><a href="https://nodejs.org/api/documentation.html" class="nav-documentation">About these Docs</a></li> <li><a href="https://nodejs.org/api/synopsis.html" class="nav-synopsis">Usage & Example</a></li> </ul> <div class="line"></div> <ul> <li><a href="https://nodejs.org/api/assert.html" class="nav-assert">Assertion Testing</a></li> <li><a href="https://nodejs.org/api/async_hooks.html" class="nav-async_hooks">Async Hooks</a></li> <li><a href="https://nodejs.org/api/buffer.html" class="nav-buffer">Buffer</a></li> <li><a href="https://nodejs.org/api/addons.html" class="nav-addons">C++ Addons</a></li> <li><a href="https://nodejs.org/api/n-api.html" class="nav-n-api">C/C++ Addons - N-API</a></li> <li><a href="https://nodejs.org/api/child_process.html" class="nav-child_process">Child Processes</a></li> <li><a href="https://nodejs.org/api/cluster.html" class="nav-cluster">Cluster</a></li> <li><a href="https://nodejs.org/api/cli.html" class="nav-cli">Command Line Options</a></li> <li><a href="https://nodejs.org/api/console.html" class="nav-console">Console</a></li> <li><a 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<li class="version-picker"> <a href="#">View another version <span>▼</span></a> <ol class="version-picker"><li><a href="https://nodejs.org/docs/latest-v12.x/api/dgram.html">12.x</a></li> <li><a href="https://nodejs.org/docs/latest-v11.x/api/dgram.html">11.x</a></li> <li><a href="https://nodejs.org/docs/latest-v10.x/api/dgram.html">10.x <b>LTS</b></a></li> <li><a href="https://nodejs.org/docs/latest-v9.x/api/dgram.html">9.x</a></li> <li><a href="https://nodejs.org/docs/latest-v8.x/api/dgram.html">8.x <b>LTS</b></a></li> <li><a href="https://nodejs.org/docs/latest-v7.x/api/dgram.html">7.x</a></li> <li><a href="https://nodejs.org/docs/latest-v6.x/api/dgram.html">6.x</a></li> <li><a href="https://nodejs.org/docs/latest-v5.x/api/dgram.html">5.x</a></li> <li><a href="https://nodejs.org/docs/latest-v4.x/api/dgram.html">4.x</a></li> <li><a href="https://nodejs.org/docs/latest-v0.12.x/api/dgram.html">0.12.x</a></li> <li><a href="https://nodejs.org/docs/latest-v0.10.x/api/dgram.html">0.10.x</a></li></ol> </li> <li class="edit_on_github"><a href="https://github.com/nodejs/node/edit/master/doc/api/dgram.md"><span class="github_icon"><svg height="16" width="16" viewBox="0 0 16.1 16.1" fill="currentColor"><path d="M8 0a8 8 0 0 0-2.5 15.6c.4 0 .5-.2.5-.4v-1.5c-2 .4-2.5-.5-2.7-1 0-.1-.5-.9-.8-1-.3-.2-.7-.6 0-.6.6 0 1 .6 1.2.8.7 1.2 1.9 1 2.4.7 0-.5.2-.9.5-1-1.8-.3-3.7-1-3.7-4 0-.9.3-1.6.8-2.2 0-.2-.3-1 .1-2 0 0 .7-.3 2.2.7a7.4 7.4 0 0 1 4 0c1.5-1 2.2-.8 2.2-.8.5 1.1.2 2 .1 2.1.5.6.8 1.3.8 2.2 0 3-1.9 3.7-3.6 4 .3.2.5.7.5 1.4v2.2c0 .2.1.5.5.4A8 8 0 0 0 16 8a8 8 0 0 0-8-8z"></path></svg></span>Edit on GitHub</a></li> </ul> </div> <hr> </header> <div id="toc"> <h2>Table of Contents</h2> <ul> <li> <p><span class="stability_2"><a href="#dgram_udp_datagram_sockets">UDP/Datagram Sockets</a></span></p> <ul> <li> <p><a href="#dgram_class_dgram_socket">Class: dgram.Socket</a></p> <ul> <li><a href="#dgram_event_close">Event: 'close'</a></li> <li><a href="#dgram_event_connect">Event: 'connect'</a></li> <li><a href="#dgram_event_error">Event: 'error'</a></li> <li><a href="#dgram_event_listening">Event: 'listening'</a></li> <li><a href="#dgram_event_message">Event: 'message'</a></li> <li><a href="#dgram_socket_addmembership_multicastaddress_multicastinterface">socket.addMembership(multicastAddress[, multicastInterface])</a></li> <li><a href="#dgram_socket_address">socket.address()</a></li> <li><a href="#dgram_socket_bind_port_address_callback">socket.bind([port][, address][, callback])</a></li> <li><a href="#dgram_socket_bind_options_callback">socket.bind(options[, callback])</a></li> <li><a href="#dgram_socket_close_callback">socket.close([callback])</a></li> <li><a href="#dgram_socket_connect_port_address_callback">socket.connect(port[, address][, callback])</a></li> <li><a href="#dgram_socket_disconnect">socket.disconnect()</a></li> <li><a href="#dgram_socket_dropmembership_multicastaddress_multicastinterface">socket.dropMembership(multicastAddress[, multicastInterface])</a></li> <li><a href="#dgram_socket_getrecvbuffersize">socket.getRecvBufferSize()</a></li> <li><a href="#dgram_socket_getsendbuffersize">socket.getSendBufferSize()</a></li> <li><a href="#dgram_socket_ref">socket.ref()</a></li> <li><a href="#dgram_socket_remoteaddress">socket.remoteAddress()</a></li> <li><a href="#dgram_socket_send_msg_offset_length_port_address_callback">socket.send(msg[, offset, length][, port][, address][, callback])</a></li> <li><a href="#dgram_socket_setbroadcast_flag">socket.setBroadcast(flag)</a></li> <li> <p><a href="#dgram_socket_setmulticastinterface_multicastinterface">socket.setMulticastInterface(multicastInterface)</a></p> <ul> <li><a href="#dgram_examples_ipv6_outgoing_multicast_interface">Examples: IPv6 Outgoing Multicast Interface</a></li> <li><a href="#dgram_example_ipv4_outgoing_multicast_interface">Example: IPv4 Outgoing Multicast Interface</a></li> <li><a href="#dgram_call_results">Call Results</a></li> </ul> </li> <li><a href="#dgram_socket_setmulticastloopback_flag">socket.setMulticastLoopback(flag)</a></li> <li><a href="#dgram_socket_setmulticastttl_ttl">socket.setMulticastTTL(ttl)</a></li> <li><a href="#dgram_socket_setrecvbuffersize_size">socket.setRecvBufferSize(size)</a></li> <li><a href="#dgram_socket_setsendbuffersize_size">socket.setSendBufferSize(size)</a></li> <li><a href="#dgram_socket_setttl_ttl">socket.setTTL(ttl)</a></li> <li><a href="#dgram_socket_unref">socket.unref()</a></li> <li><a href="#dgram_change_to_asynchronous_socket_bind_behavior">Change to asynchronous <code>socket.bind()</code> behavior</a></li> </ul> </li> <li> <p><a href="#dgram_dgram_module_functions"><code>dgram</code> module functions</a></p> <ul> <li><a href="#dgram_dgram_createsocket_options_callback">dgram.createSocket(options[, callback])</a></li> <li><a href="#dgram_dgram_createsocket_type_callback">dgram.createSocket(type[, callback])</a></li> </ul> </li> </ul> </li> </ul> </div> <div id="apicontent"> <h1>UDP/Datagram Sockets<span><a class="mark" href="#dgram_udp_datagram_sockets" id="dgram_udp_datagram_sockets">#</a></span></h1> <p></p><div class="api_stability api_stability_2"><a href="https://nodejs.org/api/documentation.html#documentation_stability_index">Stability: 2</a> - Stable</div><p></p> <p>The <code>dgram</code> module provides an implementation of UDP Datagram sockets.</p> <pre><code class="language-js">const dgram = require('dgram'); const server = dgram.createSocket('udp4'); server.on('error', (err) => { console.log(`server error:\n${err.stack}`); server.close(); }); server.on('message', (msg, rinfo) => { console.log(`server got: ${msg} from ${rinfo.address}:${rinfo.port}`); }); server.on('listening', () => { const address = server.address(); console.log(`server listening ${address.address}:${address.port}`); }); server.bind(41234); // Prints: server listening 0.0.0.0:41234 </code></pre> <h2>Class: dgram.Socket<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/dgram.js#L88">[src]</a><span><a class="mark" href="#dgram_class_dgram_socket" id="dgram_class_dgram_socket">#</a></span></h2> <div class="api_metadata"> <span>Added in: v0.1.99</span> </div> <ul> <li>Extends: <a href="https://nodejs.org/api/events.html#events_class_eventemitter" class="type"><EventEmitter></a></li> </ul> <p>Encapsulates the datagram functionality.</p> <p>New instances of <code>dgram.Socket</code> are created using <a href="#dgram_dgram_createsocket_options_callback"><code>dgram.createSocket()</code></a>. The <code>new</code> keyword is not to be used to create <code>dgram.Socket</code> instances.</p> <h3>Event: 'close'<span><a class="mark" href="#dgram_event_close" id="dgram_event_close">#</a></span></h3> <div class="api_metadata"> <span>Added in: v0.1.99</span> </div> <p>The <code>'close'</code> event is emitted after a socket is closed with <a href="#dgram_socket_close_callback"><code>close()</code></a>. Once triggered, no new <code>'message'</code> events will be emitted on this socket.</p> <h3>Event: 'connect'<span><a class="mark" href="#dgram_event_connect" id="dgram_event_connect">#</a></span></h3> <div class="api_metadata"> <span>Added in: v12.0.0</span> </div> <p>The <code>'connect'</code> event is emitted after a socket is associated to a remote address as a result of a successful <a href="#dgram_socket_connect_port_address_callback"><code>connect()</code></a> call.</p> <h3>Event: 'error'<span><a class="mark" href="#dgram_event_error" id="dgram_event_error">#</a></span></h3> <div class="api_metadata"> <span>Added in: v0.1.99</span> </div> <ul> <li><code>exception</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error" class="type"><Error></a></li> </ul> <p>The <code>'error'</code> event is emitted whenever any error occurs. The event handler function is passed a single <code>Error</code> object.</p> <h3>Event: 'listening'<span><a class="mark" href="#dgram_event_listening" id="dgram_event_listening">#</a></span></h3> <div class="api_metadata"> <span>Added in: v0.1.99</span> </div> <p>The <code>'listening'</code> event is emitted whenever a socket begins listening for datagram messages. This occurs as soon as UDP sockets are created.</p> <h3>Event: 'message'<span><a class="mark" href="#dgram_event_message" id="dgram_event_message">#</a></span></h3> <div class="api_metadata"> <span>Added in: v0.1.99</span> </div> <p>The <code>'message'</code> event is emitted when a new datagram is available on a socket. The event handler function is passed two arguments: <code>msg</code> and <code>rinfo</code>.</p> <ul> <li><code>msg</code> <a href="https://nodejs.org/api/buffer.html#buffer_class_buffer" class="type"><Buffer></a> The message.</li> <li> <p><code>rinfo</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a> Remote address information.</p> <ul> <li><code>address</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> The sender address.</li> <li><code>family</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> The address family (<code>'IPv4'</code> or <code>'IPv6'</code>).</li> <li><code>port</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><number></a> The sender port.</li> <li><code>size</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><number></a> The message size.</li> </ul> </li> </ul> <h3>socket.addMembership(multicastAddress[, multicastInterface])<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/dgram.js#L796">[src]</a><span><a class="mark" href="#dgram_socket_addmembership_multicastaddress_multicastinterface" id="dgram_socket_addmembership_multicastaddress_multicastinterface">#</a></span></h3> <div class="api_metadata"> <span>Added in: v0.6.9</span> </div> <ul> <li><code>multicastAddress</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> <li><code>multicastInterface</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> </ul> <p>Tells the kernel to join a multicast group at the given <code>multicastAddress</code> and <code>multicastInterface</code> using the <code>IP_ADD_MEMBERSHIP</code> socket option. If the <code>multicastInterface</code> argument is not specified, the operating system will choose one interface and will add membership to it. To add membership to every available interface, call <code>addMembership</code> multiple times, once per interface.</p> <p>When sharing a UDP socket across multiple <code>cluster</code> workers, the <code>socket.addMembership()</code> function must be called only once or an <code>EADDRINUSE</code> error will occur:</p> <pre><code class="language-js">const cluster = require('cluster'); const dgram = require('dgram'); if (cluster.isMaster) { cluster.fork(); // Works ok. cluster.fork(); // Fails with EADDRINUSE. } else { const s = dgram.createSocket('udp4'); s.bind(1234, () => { s.addMembership('224.0.0.114'); }); } </code></pre> <h3>socket.address()<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/dgram.js#L716">[src]</a><span><a class="mark" href="#dgram_socket_address" id="dgram_socket_address">#</a></span></h3> <div class="api_metadata"> <span>Added in: v0.1.99</span> </div> <ul> <li>Returns: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></li> </ul> <p>Returns an object containing the address information for a socket. For UDP sockets, this object will contain <code>address</code>, <code>family</code> and <code>port</code> properties.</p> <h3>socket.bind([port][, address][, callback])<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/dgram.js#L203">[src]</a><span><a class="mark" href="#dgram_socket_bind_port_address_callback" id="dgram_socket_bind_port_address_callback">#</a></span></h3> <div class="api_metadata"> <span>Added in: v0.1.99</span> </div> <ul> <li><code>port</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a></li> <li><code>address</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> <li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> with no parameters. Called when binding is complete.</li> </ul> <p>For UDP sockets, causes the <code>dgram.Socket</code> to listen for datagram messages on a named <code>port</code> and optional <code>address</code>. If <code>port</code> is not specified or is <code>0</code>, the operating system will attempt to bind to a random port. If <code>address</code> is not specified, the operating system will attempt to listen on all addresses. Once binding is complete, a <code>'listening'</code> event is emitted and the optional <code>callback</code> function is called.</p> <p>Specifying both a <code>'listening'</code> event listener and passing a <code>callback</code> to the <code>socket.bind()</code> method is not harmful but not very useful.</p> <p>A bound datagram socket keeps the Node.js process running to receive datagram messages.</p> <p>If binding fails, an <code>'error'</code> event is generated. In rare case (e.g. attempting to bind with a closed socket), an <a href="https://nodejs.org/api/errors.html#errors_class_error"><code>Error</code></a> may be thrown.</p> <p>Example of a UDP server listening on port 41234:</p> <pre><code class="language-js">const dgram = require('dgram'); const server = dgram.createSocket('udp4'); server.on('error', (err) => { console.log(`server error:\n${err.stack}`); server.close(); }); server.on('message', (msg, rinfo) => { console.log(`server got: ${msg} from ${rinfo.address}:${rinfo.port}`); }); server.on('listening', () => { const address = server.address(); console.log(`server listening ${address.address}:${address.port}`); }); server.bind(41234); // Prints: server listening 0.0.0.0:41234 </code></pre> <h3>socket.bind(options[, callback])<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/dgram.js#L203">[src]</a><span><a class="mark" href="#dgram_socket_bind_options_callback" id="dgram_socket_bind_options_callback">#</a></span></h3> <div class="api_metadata"> <span>Added in: v0.11.14</span> </div> <ul> <li> <p><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a> Required. Supports the following properties:</p> <ul> <li><code>port</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a></li> <li><code>address</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> <li><code>exclusive</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type"><boolean></a></li> <li><code>fd</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a></li> </ul> </li> <li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a></li> </ul> <p>For UDP sockets, causes the <code>dgram.Socket</code> to listen for datagram messages on a named <code>port</code> and optional <code>address</code> that are passed as properties of an <code>options</code> object passed as the first argument. If <code>port</code> is not specified or is <code>0</code>, the operating system will attempt to bind to a random port. If <code>address</code> is not specified, the operating system will attempt to listen on all addresses. Once binding is complete, a <code>'listening'</code> event is emitted and the optional <code>callback</code> function is called.</p> <p>The <code>options</code> object may contain a <code>fd</code> property. When a <code>fd</code> greater than <code>0</code> is set, it will wrap around an existing socket with the given file descriptor. In this case, the properties of <code>port</code> and <code>address</code> will be ignored.</p> <p>Specifying both a <code>'listening'</code> event listener and passing a <code>callback</code> to the <code>socket.bind()</code> method is not harmful but not very useful.</p> <p>The <code>options</code> object may contain an additional <code>exclusive</code> property that is used when using <code>dgram.Socket</code> objects with the <a href="https://nodejs.org/api/cluster.html"><code>cluster</code></a> module. When <code>exclusive</code> is set to <code>false</code> (the default), cluster workers will use the same underlying socket handle allowing connection handling duties to be shared. When <code>exclusive</code> is <code>true</code>, however, the handle is not shared and attempted port sharing results in an error.</p> <p>A bound datagram socket keeps the Node.js process running to receive datagram messages.</p> <p>If binding fails, an <code>'error'</code> event is generated. In rare case (e.g. attempting to bind with a closed socket), an <a href="https://nodejs.org/api/errors.html#errors_class_error"><code>Error</code></a> may be thrown.</p> <p>An example socket listening on an exclusive port is shown below.</p> <pre><code class="language-js">socket.bind({ address: 'localhost', port: 8000, exclusive: true }); </code></pre> <h3>socket.close([callback])<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/dgram.js#L686">[src]</a><span><a class="mark" href="#dgram_socket_close_callback" id="dgram_socket_close_callback">#</a></span></h3> <div class="api_metadata"> <span>Added in: v0.1.99</span> </div> <ul> <li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> Called when the socket has been closed.</li> </ul> <p>Close the underlying socket and stop listening for data on it. If a callback is provided, it is added as a listener for the <a href="#dgram_event_close"><code>'close'</code></a> event.</p> <h3>socket.connect(port[, address][, callback])<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/dgram.js#L348">[src]</a><span><a class="mark" href="#dgram_socket_connect_port_address_callback" id="dgram_socket_connect_port_address_callback">#</a></span></h3> <div class="api_metadata"> <span>Added in: v12.0.0</span> </div> <ul> <li><code>port</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a></li> <li><code>address</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> <li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> Called when the connection is completed or on error.</li> </ul> <p>Associates the <code>dgram.Socket</code> to a remote address and port. Every message sent by this handle is automatically sent to that destination. Also, the socket will only receive messages from that remote peer. Trying to call <code>connect()</code> on an already connected socket will result in an <a href="https://nodejs.org/api/errors.html#errors_err_socket_dgram_is_connected"><code>ERR_SOCKET_DGRAM_IS_CONNECTED</code></a> exception. If <code>address</code> is not provided, <code>'127.0.0.1'</code> (for <code>udp4</code> sockets) or <code>'::1'</code> (for <code>udp6</code> sockets) will be used by default. Once the connection is complete, a <code>'connect'</code> event is emitted and the optional <code>callback</code> function is called. In case of failure, the <code>callback</code> is called or, failing this, an <code>'error'</code> event is emitted.</p> <h3>socket.disconnect()<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/dgram.js#L423">[src]</a><span><a class="mark" href="#dgram_socket_disconnect" id="dgram_socket_disconnect">#</a></span></h3> <div class="api_metadata"> <span>Added in: v12.0.0</span> </div> <p>A synchronous function that disassociates a connected <code>dgram.Socket</code> from its remote address. Trying to call <code>disconnect()</code> on an already disconnected socket will result in an <a href="https://nodejs.org/api/errors.html#errors_err_socket_dgram_not_connected"><code>ERR_SOCKET_DGRAM_NOT_CONNECTED</code></a> exception.</p> <h3>socket.dropMembership(multicastAddress[, multicastInterface])<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/dgram.js#L812">[src]</a><span><a class="mark" href="#dgram_socket_dropmembership_multicastaddress_multicastinterface" id="dgram_socket_dropmembership_multicastaddress_multicastinterface">#</a></span></h3> <div class="api_metadata"> <span>Added in: v0.6.9</span> </div> <ul> <li><code>multicastAddress</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> <li><code>multicastInterface</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li> </ul> <p>Instructs the kernel to leave a multicast group at <code>multicastAddress</code> using the <code>IP_DROP_MEMBERSHIP</code> socket option. This method is automatically called by the kernel when the socket is closed or the process terminates, so most apps will never have reason to call this.</p> <p>If <code>multicastInterface</code> is not specified, the operating system will attempt to drop membership on all valid interfaces.</p> <h3>socket.getRecvBufferSize()<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/dgram.js#L887">[src]</a><span><a class="mark" href="#dgram_socket_getrecvbuffersize" id="dgram_socket_getrecvbuffersize">#</a></span></h3> <div class="api_metadata"> <span>Added in: v8.7.0</span> </div> <ul> <li>Returns: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><number></a> the <code>SO_RCVBUF</code> socket receive buffer size in bytes.</li> </ul> <h3>socket.getSendBufferSize()<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/dgram.js#L892">[src]</a><span><a class="mark" href="#dgram_socket_getsendbuffersize" id="dgram_socket_getsendbuffersize">#</a></span></h3> <div class="api_metadata"> <span>Added in: v8.7.0</span> </div> <ul> <li>Returns: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><number></a> the <code>SO_SNDBUF</code> socket send buffer size in bytes.</li> </ul> <h3>socket.ref()<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/dgram.js#L857">[src]</a><span><a class="mark" href="#dgram_socket_ref" id="dgram_socket_ref">#</a></span></h3> <div class="api_metadata"> <span>Added in: v0.9.1</span> </div> <p>By default, binding a socket will cause it to block the Node.js process from exiting as long as the socket is open. The <code>socket.unref()</code> method can be used to exclude the socket from the reference counting that keeps the Node.js process active. The <code>socket.ref()</code> method adds the socket back to the reference counting and restores the default behavior.</p> <p>Calling <code>socket.ref()</code> multiples times will have no additional effect.</p> <p>The <code>socket.ref()</code> method returns a reference to the socket so calls can be chained.</p> <h3>socket.remoteAddress()<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/dgram.js#L728">[src]</a><span><a class="mark" href="#dgram_socket_remoteaddress" id="dgram_socket_remoteaddress">#</a></span></h3> <div class="api_metadata"> <span>Added in: v12.0.0</span> </div> <ul> <li>Returns: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a></li> </ul> <p>Returns an object containing the <code>address</code>, <code>family</code>, and <code>port</code> of the remote endpoint. It throws an <a href="https://nodejs.org/api/errors.html#errors_err_socket_dgram_not_connected"><code>ERR_SOCKET_DGRAM_NOT_CONNECTED</code></a> exception if the socket is not connected.</p> <h3>socket.send(msg[, offset, length][, port][, address][, callback])<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/dgram.js#L546">[src]</a><span><a class="mark" href="#dgram_socket_send_msg_offset_length_port_address_callback" id="dgram_socket_send_msg_offset_length_port_address_callback">#</a></span></h3> <div class="api_metadata"> <details class="changelog"><summary>History</summary> <table> <tbody><tr><th>Version</th><th>Changes</th></tr> <tr><td>v12.0.0</td> <td><p>Added support for sending data on connected sockets.</p></td></tr> <tr><td>v8.0.0</td> <td><p>The <code>msg</code> parameter can be an <code>Uint8Array</code> now.</p></td></tr> <tr><td>v8.0.0</td> <td><p>The <code>address</code> parameter is always optional now.</p></td></tr> <tr><td>v6.0.0</td> <td><p>On success, <code>callback</code> will now be called with an <code>error</code> argument of <code>null</code> rather than <code>0</code>.</p></td></tr> <tr><td>v5.7.0</td> <td><p>The <code>msg</code> parameter can be an array now. Also, the <code>offset</code> and <code>length</code> parameters are optional now.</p></td></tr> <tr><td>v0.1.99</td> <td><p><span>Added in: v0.1.99</span></p></td></tr> </tbody></table> </details> </div> <ul> <li><code>msg</code> <a href="https://nodejs.org/api/buffer.html#buffer_class_buffer" class="type"><Buffer></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array" class="type"><Uint8Array></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array" class="type"><Array></a> Message to be sent.</li> <li><code>offset</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> Offset in the buffer where the message starts.</li> <li><code>length</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> Number of bytes in the message.</li> <li><code>port</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> Destination port.</li> <li><code>address</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> Destination hostname or IP address.</li> <li><code>callback</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> Called when the message has been sent.</li> </ul> <p>Broadcasts a datagram on the socket. For connectionless sockets, the destination <code>port</code> and <code>address</code> must be specified. Connected sockets, on the other hand, will use their associated remote endpoint, so the <code>port</code> and <code>address</code> arguments must not be set.</p> <p>The <code>msg</code> argument contains the message to be sent. Depending on its type, different behavior can apply. If <code>msg</code> is a <code>Buffer</code> or <code>Uint8Array</code>, the <code>offset</code> and <code>length</code> specify the offset within the <code>Buffer</code> where the message begins and the number of bytes in the message, respectively. If <code>msg</code> is a <code>String</code>, then it is automatically converted to a <code>Buffer</code> with <code>'utf8'</code> encoding. With mes