function get_clientip()
{
    if(isset($_SERVER["HTTP_CF_CONNECTING_IP"]))
    {
        $_SERVER['REMOTE_ADDR'] = $_SERVER["HTTP_CF_CONNECTING_IP"];
        $_SERVER['HTTP_CLIENT_IP'] = $_SERVER["HTTP_CF_CONNECTING_IP"];
    }

    $client  = @$_SERVER['HTTP_CLIENT_IP'];
    $remote  = $_SERVER['REMOTE_ADDR'];
    $forward = @$_SERVER['HTTP_X_FORWARDED_FOR'];

    if(filter_var($client, FILTER_VALIDATE_IP))
    {
        $ip = $client;
    }
    elseif(filter_var($forward, FILTER_VALIDATE_IP))
    {
        $ip = $forward;
    }
    else
    {
        $ip = $remote;
    }

    return $ip;
}

function save_comment_hostip($comment_id)
{
    $hostIP = get_clientip();
    $partIP = explode('.', $clientIP);
    $hideIP = $partIP[0].'.'.$partIP[1].'***.***';

    if((isset($hideIP)) && ($hideIP != ''))
    {
        add_comment_meta($comment_id, 'host_ip', $hideIP);
    }
}

add_action('comment_post', 'save_comment_hostip', 5);

?>