Instead of (I presume this is where it's failing):

    $sock->send($request) or die "send: $!";
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Try something more along the lines of:

    unless ($_=$sock->send($request)) {
        die "send: $!"
          unless $! =~ /unreachable/;  # Or whatever
        sleep 1;
    }
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Maybe throw a counter in there so it only sleeps/retries a maximum number of times.