【求助】救火啊各位大虾帮忙看看这题

smallrain

<P>各位大虾帮忙看看这题,我怎么看都觉得是A<BR>What is the advantage of using a multipoint interface instead of point-to-point<BR>subinterfaces when configuring a Frame Relay hub in a hub-and-spoke topology?<BR>A. it avoids split-horizon issues with distance vector routing protocols.<BR>B. IP addresses can be conserved if VLSM is not being used for subnetting.<BR>C. A multipoint interface offers greater security compared to point-to-point subinterface<BR>configurations.<BR>D. The multiple IP network addresses required for a multipoint interface provide greater<BR>addressing flexibility over point-to-point configurations.<BR>Answer: B</P><p>［此帖子已被 风行无际 在 2006-8-8 22:27:54 编辑过］

smallrain

One type of frame switching uses low-latency forwarding and then switches to a<BR>higher-latency error checking mode when an error threshold is exceeded. What is<BR>the name of this frame switching mode?<BR>A. store and forward<BR>B. fragment-free<BR>C. adaptive cut-through<BR>D. fast-forward<BR>Answer: C

头点什么

<P><FONT face=Arial color=#2222dd>第一题，A选项的避免水平分割问题是点对点子接口的优点，B选项才是多点接口的优势``</FONT></P><P><FONT face=Arial color=#2222dd>第二题说的是一种自适应的直通转发模式，默认时使用低时延转发，当超过一个错误门限值后转变为高时延错误检查模式。</FONT></P><P><FONT face=Arial color=#2222dd>看一下Cisco官方的解释</FONT></P><P><FONT face=Arial>Adaptive Cut-Through<BR>With adaptive cut-through mode, the user can configure the switch to automatically use the best forwarding mode based on user-defined thresholds. In adaptive cut-through mode, the ports operate in cut-through mode unless the number of forwarded frames that contain errors exceeds a specified percentage. When this percentage is exceeded, the switch automatically changes the mode of the port to store-and-forward. Then, once the percentage of frames containing errors falls below a specified percentage, the operation mode of the ports is once again set to cut-through.</FONT></P>

尐嫻

<P>头点什么是论坛英雄！！！！！<IMG src="http://www.spoto.net/bbs/images/Emotions/28.gif">&nbsp;</P><P>（刺激大东说的！ 哈哈 ）</P>