# 第四部分：网络通讯

FreeBSD 是最广泛部署在高性能网络服务器上的操作系统之一。本部分的章节包括：

* 串行通信
* PPP 和 PPP 通过以太网
* 电子邮件
* 运行网络服务器
* 防火墙
* 其他高级网络主题

这些章节设计成在需要信息时阅读。不需要按特定顺序阅读，也不必在在网络环境中使用 FreeBSD 之前阅读所有章节。


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