Firewall can effectively protect your Mac computer from unauthorized network access。Here are the steps to turn on and configure the firewall on your Mac computer。 step one：打开系统偏好设置 1.点击屏幕左上角的苹果图标，Select "System Preferences"。 Step 2：进入安全性与隐私 2.在系统偏好设置中，Click "Security & Privacy"。 Step 3：解锁设置 3.点击左下角的锁图标，and enter the administrator password to unlock settings。 Step 4：打开防火墙 4.选择“防火墙”选项卡，Click the "Turn on firewall" button。 Step 5：配置防火墙 5.点击“防火墙选项…”按钮，Make further configuration。您可以选择允许或阻止特定...