Get "The remote server returned an error: (500) Syntax error, command unrecognized" when I try to run FtpWebRequest.GetRequestStream

Question

I have following code to send files to a FTP server.

function FtpUploader(
  [string]$uri,
  [string]$localeFile,
  [string]$user = "ftp",
  [string]$password = "ftp",
  [int]   $timeout  = 20000
){
    trap {
      Write-Host ("ERROR: " + $_) -Foregroundcolor Red
      return $false 
    }

    $ftp             = [System.Net.FtpWebRequest]::Create($uri)
    $ftp             = [System.Net.FtpWebRequest]$ftp
    $ftp.Method      = [System.Net.WebRequestMethods+Ftp]::UploadFile
    $ftp.Credentials = new-object System.Net.NetworkCredential($user, $password)  
    $ftp.Timeout     = $timeout
    $ftp.UseBinary   = $false
    $ftp.UsePassive  = $true

    $content         = Get-Content -en byte $localeFile

    $rs              = $ftp.GetRequestStream()
    $rs.Write($content, 0, $content.Length)

    $rs.Close()
    $rs.Dispose()

    return $true
}

The URI I use is "ftp://xxx.xxx.xxx.xxx/aaa/bbb/ccc/R1ACTIVE.TXT". The FTP server is vsftpd

Most of the time, the file is uploaded. But sometime I get following error when it try to run $ftp.GetRequestStream():

The remote server returned an error: (500) Syntax error, command unrecognized.

Why???

Answer 1

Have you tried using system.net.webclient instead of the ftpwebrequest?

function FtpUploader( 
  [string]$uri, 
  [string]$localeFile, 
  [string]$user = "ftp", 
  [string]$password = "ftp", 
  [int]   $timeout  = 20000 
){ 
    trap { 
      Write-Host ("ERROR: " + $_) -Foregroundcolor Red 
      return $false  
    } 

    $ftp             = New-Object System.Net.Webclient  
    $ftp.Credentials = new-object System.Net.NetworkCredential($user, $password)   

    $result = $ftp.UploadFile($uri, (Resolve-Path $localeFile)) 

    return $true 
}

Answer 2

I did solve it by using:

$ftp.KeepAlive   = $false