问题 问答题 简答题

OSPF协议有几种报文类型,分别是什么?

答案

参考答案:

Hello:在规定的间隔内发送,用来建立和保持邻站关系。

Database description:描述拓扑数据库的内容。当毗邻关系确定时发送。

Link state request:请求发送邻站的拓扑数据库。当一个路由器发现它的拓扑数据库部分内容过时时(通过数据库描述报文),发送该类报文。

Link state update:是对链接状态请求报文的回答。但它们也被用来定期地发布LSA。多个LSA可以包含在一个报文中。

Link state acknowledgment:确认链接状态更新报文。链接状态更新报文必须被显式地 确认,确保一个区域内的链接状态传播可靠地进行。

阅读理解

根据短文内容判断正误。正确的写T,错误的写 F。

       Do you use your right hand more or left hand more? Very few us use both of our hands well. Most

 people use right hands, only about five people of a hundred use left hands.  New-born babies can take

  things with either of their hands, but in about two years, they like to use their right hands. Scientists don't

  know why this happens. Thcy've studied it. They think our animal ancestors used their right hands, this

 may not be true.  Monkeys are our closest. relation in the animal world. Scientists have found that

 monkeys like to use one of their hands more than the other. but it can be either hand.  There are as many

  right-handed monkeys as the left-handed ones. Next time you visit the zoo and watch the monkeys

 carefully. You'Il see that some of them will use their right hands and others will use their lcft hands, but

 men use their right hands better and this makes life difficult for the lefthanded ones.  We live in a

 right-handed world.

    Some scientists have found out that more of successful people are left-handed, but they don't know

 why.  But they are working hard to discover the secret.

( ) 1. Very few of us use both of our hands.

( ) 2. About 5% people use their left hands.

( ) 3. The left-handed live easily because most people use their left hands.

( ) 4. New-born babies use their right hands more.

( ) 5. Scientists don't know the reason why more of successful people are lcft-handed.

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