wget(1) --retry-connrefused -bqc http://path.com/url.iso
The non-interactive network downloader
--retry-connrefused
    Consider "connection refused" a transient error and try again.  Normally Wget gives up on a URL when
    it is unable to connect to the site because failure to connect is taken as a sign that the server is
    not running at all and that retries would not help.  This option is for mirroring unreliable sites
    whose servers tend to disappear for short periods of time.
-b
--background
    Go to background immediately after startup.  If no output file is specified via the -o, output is
    redirected to wget-log.
-q
--quiet
    Turn off Wget's output.
-c
--continue
    Continue getting a partially-downloaded file.  This is useful when you want to finish up a download
    started by a previous instance of Wget, or by another program.  For instance:
wget [option]... [URL]...
source manpages: wget