交换机access trunk hybrid模式详解

前言：

本文涵盖以下内容：交换机内部示意图；VLAN的含义与帧格式；port的access trunk hybrid三种工作模式；交换机级联和堆叠的区别？

交换机示意图

先来看一张交换机实物图：

接下来是示意图，这里例举示意图的目的仅仅是为了方面下面对端口输入输出的描述：

P = Port；1-48代表1到48口。

Vlan的含义与帧格式

VLAN —— 虚拟局域网

Wiki上对VLAN（Virtual Local Area Network）的释义：

In computer networking, a single layer-2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them via one or more routers; such a domain is referred to as a Virtual Local Area Network, Virtual LAN or VLAN.

VLAN是在