access port 与portfast之间的关系

问题：

Hey..

Can anyone please help me understand why setting ports to be access ports (switchport mode access) does not accomplish the same thing as Portfast?

I guess I am trying to understand why they are 2 separate commands. Wouldn't setting the port to be an Access port be good enough to tell the switch that loops cannot occur on those port since they are Access ports (therefore allowing those access ports to bypass the listening/learning states)?

Thank you.

回答：

The confusion you are having stems from the fact that you think that access ports are meant for connecting end user devices like computers or printers.

Well, that is just wrong.

You can have a HUB or a Switch connected to an access port.

The same idea applies for Trunks. You can connect any type of device to a Trunk port as long as the NIC inserted into ssaid device can handle the trunking tagging/encapsulation of frames traversing the trunk.

In other words, you may have switches connected to Access ports and say, servers connected to Trunk ports.

Applying the Access or Trunk configuration on a port only instructs the switch to either handle one or many vlans on said port. It is not telling the switch the nature of devices you will connect to said port.

That is why PortFast comes as a separate command. Configuring Portfast on a port tells the switch that you are not connecting into said port, a device capable of creating a layer 2 loops on your network.

Contrary to what people believe, you can apply the PortFast command to a trunk port if such trunk is connected say, to a server. And you should not configure PortFast to an access port connected to a Hub.

本文转自zcm8483 51CTO博客，原文链接:http://blog.51cto.com/haolun/991596

access port 与portfast之间的关系相关推荐

Spring各模块的功能及互相之间的关系
目录 spring-framework 的源码目录 Spring FrameWork 结构图各个模块功能(该部分参考结构图来看) 模块概述(该部分参考源码目录来看) 核心容器 AOP和Instrum ...
WSGI、Flask及Werkzeug三者之间的关系
目录一.WSGI是什么? 二.Werkzeug是什么三.Flask的WSGI实现一.WSGI是什么? WSGI是一套接口规范.一个WSGI程序用以接受客户端请求,传递给应用,再返回服务器的响应给 ...
.NET Core 和 .NET Framework 之间的关系
引用一段描述:Understanding the relationship between .NET Core and the .NET Framework. .NET Core and the .N ...
JVM与计算机之间的关系
计算机内存硬件架构 CPU,一台现代计算机拥有两个或多个CPU,其中一些CPU还有多核,从这一点可以看出,在一个有两个或多个CPU的现代计算机上,同时运行多个线程是非常有可能的,而且每个CPU在某一个 ...
UML图中类之间的关系:依赖,泛化,关联,聚合,组合,实现
类与类图 1) 类(Class)封装了数据和行为,是面向对象的重要组成部分,它是具有相同属性.操作.关系的对象集合的总称. 2) 在系统中,每个类具有一定的职责,职责指的是类所担任的任务,即类要完成什 ...
分布式系统 - CAP, BASE, ACID之间的关系 - 学习/实践
1.应用场景主要用于学习分布式系统中CAP, BASE, ACID之间的关系,理清各自的应用场景. 2.学习/操作 1.文档阅读 22 | 想成为架构师,你必须知道CAP理论-极客时间 23 | 想 ...
RunLoop总结：RunLoop 与GCD 、Autorelease Pool之间的关系
如果在面试中问到RunLoop相关的知识,很有可能也会问到RunLoop与GCD.Autorelease Pool有没有关系,哪些地方用到了GCD.Autorelease Pool等. So,本文就总 ...
strongswan libstrongswan scheduler,processor,job,event和thread之间的关系
目录 scheduler介绍 scheduler调度的event与job的关系 scheduler的主要操作 job又是如何创建的呢? job的执行 scheduler介绍 scheduler使用he ...
Python进阶----表与表之间的关系(一对一,一对多,多对多),增删改查操作
Python进阶----表与表之间的关系(一对一,一对多,多对多),增删改查操作,单表查询,多表查询一丶表与表之间的关系背景: 由于如果只使用一张表存储所有的数据,就会操作数 ...

access port 与portfast之间的关系

access port 与portfast之间的关系相关推荐

最新文章

热门文章