Your problem is that "monthly" is not a child of root ("config"); it is a child of "traffic". I think you want this: 
my @ids;
my $t = XML::Twig->new();
$t->parse($xmlStr);
for my $one ($t->root()->children('one')) {
    if ($one->first_child('traffic')->first_child('monthly')->att('val
+ue') eq 'on') {
        push @ids, $one->att('id') 
    }
}
print Dumper(\@ids);

__END__

$VAR1 = [
          'movies',
          'espn'
        ];

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In reply to Re^4: trying to understand xml::twig and also trying to learn how to extract attribute by toolic
in thread trying to understand xml::twig and also trying to learn how to extract attribute by convenientstore

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