NUMBER:
for (3 .. 8) {
        my $pdu_num = $_;
        $pdu_num = 11 - $pdu_num unless defined $order;
        while (@nodes) {
                my $node = shift @nodes;
                $map{$node} = $pdu . '['.$pdu_num.']';
                next NUMBER;
        }
}

##</code><code>##

for my $pdu_num (3 .. 8) {
    while my $node (@nodes) {
        # more code here...
    }
}