sub verify_ether($){
    my $mac = uc(shift);
    $mac =~ s/-/:/g;

    my @octets;

    if($mac =~ /^[0-9A-F]{12}$/){
        $mac = join(':', unpack("A2" x 6, $mac));
    }elsif ($mac =~  /^(([0-9A-F]{1,2}?):){5}([0-9A-F]{1,2})$/ ){
        @octets = split(/:/, $mac);
        map { if (length($_)==1) { $_ = "0" . $_ } } @octets;
        $mac = join(':', @octets);
    }else{
        return undef;
    }
    return $mac;
}