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.

wget [option]... [URL]...

-t number
--tries=number
    Set number of retries to number.  Specify 0 or inf for infinite retrying.  The default is to retry 20
    times, with the exception of fatal errors like "connection refused" or "not found" (404), which are
    not retried.