很容易认为您的Mac在互联网上是安全可靠的。尽管macOS不像Windows那样容易受到攻击，但Mac用户仍应考虑使用防火墙来保护他们的计算机免受不必要的入侵。
您应该使用的第一层保护是防火墙，它可以阻止应用程序和服务访问您的计算机。使用以下步骤配置您的Mac 防火墙(Mac Firewall)。
什么是防火墙？
防火墙(firewall)充当您的计算机与 Internet 上的恶意软件之间的屏障。它通过阻止访问您的计算机并仅允许您信任的那些应用程序和服务来保护您的计算机。
macOS 有一个内置的防火墙，我们建议您使用它来代替第三方防火墙或防病毒软件。这些第三方软件包在 macOS 上运行，可能会降低您的系统速度。macOS 版本对计算机性能的影响很小。它在后台运行，你甚至不知道它的存在。
如何启用 Mac 防火墙
与大多数 macOS 设置一样，防火墙控制面板位于 macOS 的系统偏好设置中。防火墙只需几个步骤即可启用。使用以下说明打开Mac 防火墙(Mac Firewall)，然后根据需要进行配置。
- 选择左上角的Apple 菜单，然后选择(Apple menu)System Preferences。
- 选择安全和隐私(Security & Privacy)。
- 选择防火墙(Firewall)选项卡。
- 选择左下角的锁定图标以解锁设置。(lock icon)
- 出现提示时输入(Enter)管理员名称和密码。
- 选择打开防火墙(Turn On Firewall)。
这将使用默认设置启用Mac 防火墙。(Mac Firewall)大多数应用程序将被阻止，但某些系统应用程序、服务和进程可能会通过防火墙(Firewall)。如果一切都按预期工作，您可以开始使用您的计算机并忘记防火墙(Firewall)，因为它知道它可以保护您的安全。
如何配置 Mac 防火墙
您需要打开Mac 防火墙(Mac Firewall)，然后对其进行配置，这样您的基本应用程序就不会被阻止。您可能还想阻止可能构成威胁的应用程序和服务。
- 选择左上角的Apple 菜单，然后选择(Apple menu)System Preferences。
- 选择安全和隐私(Security & Privacy)。
- 选择防火墙(Firewall)选项卡。
- 选择左下角的锁定图标以解锁设置。(lock icon)
- 出现提示时输入(Enter)管理员名称和密码。
- 选择防火墙选项(Firewall Options)以配置防火墙
- 您可以在防火墙(Firewall)选项中更改一些设置。第一个是阻止所有 Internet 连接(Block All Internet Connections)。此设置会阻止所有传入连接，并且只有在您知道不会使用任何依赖传入连接的 文件共享、远程访问或类似应用程序时才应更改此设置。(file sharing)
- 您可以更改的下一个设置是Add +。这使您可以添加应用程序或服务，然后可以将其设置为允许传入连接(Allow incoming connections)或阻止传入连接(Block incoming connections)。您还可以选择删除 –(Remove –)从Mac 防火墙(Mac Firewall)中删除服务或应用程序。
- 接下来的两个部分，自动允许内置软件接收传入连接(Automatically allow built-in software to receive incoming connections )和自动允许下载的签名软件接收传入连接( Automatically allow downloaded signed software to receive incoming connections)，默认启用。这些设置会自动将受信任的应用程序和受信任的应用程序添加到防火墙的允许应用程序列表中。
这是一个方便的功能，可以添加这些条目，而无需您授权您安装的每个应用程序或服务。我们建议您启用它们，除非您希望对授予您安装的应用程序的防火墙访问权限进行精细控制。
- 接下来是启用隐身模式(Enable Stealth Mode)。此隐身模式设置(stealth mode setting)告诉您的Mac忽略传入的连接，这些连接正在 ping 您的计算机并在未经授权的情况下询问信息。此选项阻止来自黑客和恶意软件的未经授权的请求，但不会阻止来自授权的应用程序和服务的请求。
您通常不需要在家中启用此设置，因为大多数家庭路由器都提供类似的保护。如果您绕过路由器并直接连接到 Internet，则启用此设置可能是个好主意。在使用不安全的公共网络时，它也可能会有所帮助。
- 完成更改后，您可以选择OK。
- 最后但并非最不重要的是高级设置(Advanced Settings)菜单，可用于进一步保护您的计算机。在大多数情况下，这些设置(these settings)不需要更改。它们允许您限制用户在 Mac 空闲时登录到Mac的时间，并限制用户在没有管理员级别密码的情况下更改锁定的系统偏好设置。
使用 Mac 防火墙(Using the Mac Firewall)
不谈防火墙就谈不上家庭网络安全。这是抵御外来攻击的第一道防线。它阻止未经授权的流量并防止恶意软件感染您的计算机。Mac 防火墙(Mac Firewall)是免费的。
它在保护计算机数据(computer’s data)方面做得不错，几乎不会影响计算机的性能。如果您在互联网上花费大量时间，您应该强烈考虑启用Mac 防火墙(Mac Firewall)。如果您使用笔记本电脑访问公共场所，则更为重要。
macOS 中的防火墙(Firewall)很容易打开/关闭，因此如果您决定不希望它在后台运行，您可以在不到一分钟的时间内将其关闭。
Mac Firewall: How to Enable and Configure It
It’s easy to think that your Mac is safe and secure on the internеt. Though macOS is not as vulnerable as Windows, Mac owners still should consider using a firewall to protect their computers from unwanted intrusion.
The first layer of protection you should use is a firewall, which blocks apps and services from accessing your computer. Use the steps below to configure your Mac Firewall.
What is a Firewall?
A firewall functions as a barrier between your computer and nefarious software on the internet. It protects your computer by blocking access to your computer and allowing only those apps and services that you trust.
macOS has a built-in firewall that we recommend you use instead of a third-party firewall or antivirus software. These third-party software packages run on top of macOS and may slow down your system. The macOS version has a minimal effect on your computer’s performance. It runs in the background, and you don’t even know that it’s there.
How to Enable the Mac Firewall
Like most macOS settings, the firewall control panel is found in the system preferences for macOS. The firewall only takes a few steps to enable. Use the directions below to turn on the Mac Firewall and then configure it if needed.
- Select the Apple menu in the upper left corner and then select System Preferences.
- Select Security & Privacy.
- Select the Firewall tab.
- Select the lock icon in the lower-left corner to unlock the settings.
- Enter the administrator name and password when prompted.
- Select Turn On Firewall.
This will enable the Mac Firewall with the default settings. Most apps will be blocked, though some system apps, services, and processes may pass through the Firewall. If everything is working as expected, you can start using your computer and forget the Firewall knowing that it keeps you safe.
How to Configure the Mac Firewall
You need to turn on the Mac Firewall and then configure it so your essential apps are not blocked. You may also want to block apps and services that may pose a threat.
- Select the Apple menu in the upper left corner and then select System Preferences.
- Select Security & Privacy.
- Select the Firewall tab.
- Select the lock icon in the lower-left corner to unlock the settings.
- Enter the administrator name and password when prompted.
- Select Firewall Options to configure the Firewall
- There are a handful of settings that you can change within the Firewall options. The first is Block All Internet Connections. This setting blocks all incoming connections and should only be changed if you know you won’t be using any file sharing, remote access, or similar apps that rely on an incoming connection.
- The next setting you can change is Add +. This lets you add an app or service which then can be set to Allow incoming connections or Block incoming connections. You also can select the Remove – to delete a service or app from the Mac Firewall.
- The next two sections, Automatically allow built-in software to receive incoming connections and Automatically allow downloaded signed software to receive incoming connections, are enabled by default. These settings automatically add trusted apps and trusted to the Firewall’s list of allowed apps.
This is a convenient feature that adds these entries without requiring you to authorize each app or service you install. We recommend leaving them enabled unless you want granular control over the firewall access granted to the apps you install.
- Up next is Enable Stealth Mode. This stealth mode setting tells your Mac to ignore incoming connections that are pinging your computer and asking for information without authorization. This option blocks unauthorized requests from hackers and malware, but it doesn’t block requests from authorized apps and services.
You typically wouldn’t need to enable this setting at home as most home routers offer similar protection. It may be a good idea to enable this setting if you bypass your router and connect directly to the internet. It may also be helpful when using insecure public networks.
- When you are done making changes, you can select OK.
- Last but not least is the Advanced Settings menu which can be used to further secure your computer. In most cases, these settings won’t need to be changed. They let you limit the amount of time a user is logged into a Mac when it’s idle, and restrict users from changing locked system preferences without an admin-level password.
Using the Mac Firewall
You can’t talk about home network security without talking about a firewall. It’s the first line of defense against outside attacks. It blocks unauthorized traffic and prevents malware from infecting your computer. The Mac Firewall is free.
It does a decent job of protecting your computer’s data and hardly affects your computer’s performance. If you spend a lot of time on the internet, you should strongly consider enabling the Mac Firewall. It’s even more important if you visit public places with your laptop.
The Firewall in macOS is easy to turn on/off, so if you decide you don’t want it running in the background, you can turn it off in less than a minute.
