JavaScript

FTP Socket Buffer and Address Options

Demonstrates the SoRcvBuf, SoSndBuf, PreferIpv6, and ClientIpAddress properties.

Background: These are low-level knobs for specific situations. Larger send/receive buffers can improve throughput on high-bandwidth, high-latency links, though the defaults suit the common case. PreferIpv6 only matters when a hostname resolves to both address families, choosing which to try first. ClientIpAddress is normally left unset; set it on a multihomed host to bind the outgoing connection to a particular local interface. Change any of these only with a concrete reason.

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

JavaScript

var success = false;

var ftp = new CkFtp2();

ftp.Hostname = "ftp.example.com";
ftp.Username = "myFtpLogin";

//  SoRcvBuf and SoSndBuf set the TCP socket receive/send buffer sizes.  The defaults are tuned for
//  the common case; larger values can sometimes help throughput on high-latency links.
ftp.SoRcvBuf = 4194304;
ftp.SoSndBuf = 524288;

//  PreferIpv6 (default false) chooses IPv6 over IPv4 when a hostname resolves to both.
ftp.PreferIpv6 = false;

//  ClientIpAddress is normally left unset; set it on a multihomed host to bind the outgoing
//  connection to a specific local interface.
ftp.ClientIpAddress = "192.168.1.50";

//  Normally you would not hard-code the password in source.  You should instead obtain it
//  from an interactive prompt, environment variable, or a secrets vault.
ftp.Password = "myPassword";

success = ftp.Connect();
if (success == false) {
    console.log(ftp.LastErrorText);
    return;
}

console.log("Connected with custom socket options.");

success = ftp.Disconnect();
if (success == false) {
    console.log(ftp.LastErrorText);
    return;
}