问题 问答题 简答题

简述不同VLAN的计算机之间的通信方式。

答案

参考答案:

不同VLAN的计算机之间无法直接互相通信。为了能够在VLAN间通信,需要利用OSI参照模型中的网络层的信息来进行路由。以下是两种实现方式:

(1)通过路由器实现VLAN间的通信:使用路由器实现VLAN间通信时,路由器与交换机的连接有两种。

第一种通过路由器的不同物理接口与交换机上的每个VLAN分别连接。

第二种通过路由器的逻辑子接口与交换机的各个VLAN连接。

(2)用交换机代替路由器实现VLAN间的通信:用交换机代替路由器实现VLAN间通信的方式也有两种。

第一种是启用交换机的路由功能,这种方式的实现方法可采用以上介绍的路由器方式的任意一种。

第二种是利用某些高端交换机所支持的专用VLAN功能来实现VLAN间的通信。

阅读理解

阅读理解。

     I made a promise to myself on the way down to the vacation beach cottage. For two weeks I would

try to be a loving husband and father. Totally loving. No ifs, ands or buts.

     The idea had come to me as I listened to a talk on my car radio. The speaker was quoting a Biblical

passage about husbands and their wives. Then he went on to say, "Love is an act of will. A person can

choose to love." To myself, I had to admit that I had been a selfish husband. Well, for two weeks that

would change.

     And it did. On arriving at the beach cottage, I kissed Evelyn meeting me at the door and said, "That

new yellow sweater looks great on you." "Oh, Tom, you noticed", she said, surprised and pleased. Maybe

a little puzzled. After the long drive, I wanted to sit and read. Evelyn suggested a walk on the beach. I

started to refuse, but then I thought, "Evelyn's been alone here with the kids all week and now she wants

to be alone with me." We walked on the beach while the children flew their kites.

     So it went. Two weeks of not calling the Wall Street firm where I am a director; a visit to the shell

museum though I usually hate museums. Relaxed and happy, that's how the whole vacation passed. I

made a new promise to keep on remembering to choose love.

     There was one thing that went wrong with my experiment, however. Evelyn and I still laugh about

it today. On the last night at our cottage, preparing for bed, Evelyn stared at me with the saddest

expression.

     "What's the matter?" I asked her.

     "Tom," she said in a voice filled with distress, "I don't?"

     "What do you mean?"

     "Well…that checkup I had several weeks ago…our doctor…did he tell you something about me?

Tom, you've been so good to me…am I dying?"

     It took a moment for it all to be understood. Then I burst out laughing.

     "No, honey," I said, wrapping her in my arms. "You're not dying; I'm just starting to live."

1. From the story we may infer that Tom drove to the beach cottage _____. [ ]

A. with his family

B. with Evelyn

C. alone

D. with his children

2. During the two weeks on the beach, Tom showed more love to his wife because _____. [ ]

A. he was determined to be a good husband

B. he had made a lot of money in his Wall Street firm

C. she looked lovely in her new clothes

D. the doctor said his wife was seriously ill

3. The author says, "There was one thing that went wrong with my experiment." What does "one thing"

     refer to? [ ]

A. He praised her sweater, which puzzled her.

B. She insisted on visiting a museum, which he hated.

C. He knew something about her illness but didn't tell her.

D. He was so good to her that she thought she must be dying.

4. By saying "I'm just starting to live," Tom means that _____. [ ]

A. he is just beginning to understand the real meaning of life

B. he is just beginning to enjoy life as a loving husband

C. he lived an unhappy life before and is now starting to change

D. he is beginning to feel regret for what he did to his wife before

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