sub same_subnet ($) {
    my $p = shift; my $net = $_[0];
    RefCheck($net, __PACKAGE__);
    TPe "ptype=%s, netptype=%s", $p->{ptype}, $net->{ptype} unless
      $p->{ptype} && $net->{ptype};
   return undef if $p->{ptype} ne $net->{ptype};   <<<----