ICMP是:Internet 控制信息协议（ICMP）是 IP 组的一个整合部分，没有具体的端口号

Myth丶恋晨 2022-07-15 10:55 62阅读 0赞

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     <h2 style="font-size:16px; vertical-align:middle; float:left">&nbsp;<strong><a title="我去面试，他问我ICMP用的是什么端口" href="http://bbs.51cto.com/thread-821402-1.html" rel="nofollow">我去面试，他问我ICMP用的是什么端口</a></strong>&nbsp;&nbsp;<a style="color:grey; font-size:12px; text-decoration:none" rel="nofollow">[复制链接]</a></h2> 
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     <p>发表于&nbsp;2011-4-8 19:33&nbsp;|&nbsp;来自&nbsp; <a title="" href="http://bbs.51cto.com/" rel="nofollow"> 51CTO网页</a> </p> 
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       ICMP是:Internet 控制信息协议（ICMP）是 IP 组的一个整合部分。通过 IP 包传送的 ICMP 信息主要用于涉及网络操作或错误操作的不可达信息。 ICMP 包发送是不可靠的，所以主机不能依靠接收 ICMP 包解决任何网络问题。ICMP不象TCP或UDP有端口，但它确实含有两个域：类型(type)和代码(code)。而且这些域的作用和端口也完全不同。 
      <br> Ping用到的是ICMP协议。不是端口。 
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      <li><cite><a href="http://bbs.51cto.com/space-uid-192876.html" rel="nofollow">独钩寒江雪</a></cite> 无忧币 <strong>+3</strong> <em>辛苦花生了</em> 2011-4-8 21:14 </li> 
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     <div>
       ICMP是:Internet 控制信息协议（ICMP）是 IP 组的一个整合部分，没有具体的端口号。通过 IP 包传送的 ICMP 信息主要用于涉及网络操作或错误操作的不可达信息。 ICMP 包发送是不可靠的，所以主机不能依靠接收 ICMP 包解决任何网络问题。 
      <br> 比如，某台主机或整个网络由于某些故障不可达，必有指向某个端口号的 TCP 或 UDP 包，即也就是LZ所提到的端口号 
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      <li><cite><a href="http://bbs.51cto.com/space-uid-192876.html" rel="nofollow">独钩寒江雪</a></cite> 无忧币 <strong>+3</strong> <em>热心广援</em> 2011-4-8 21:15 </li> 
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     <p>发表于&nbsp;2011-4-8 21:18&nbsp;|&nbsp;来自&nbsp; <a title="" href="http://bbs.51cto.com/" rel="nofollow"> 51CTO网页</a> </p> 
     <p><a href="http://bbs.51cto.com/viewthread.php?tid=821402&amp;page=1&amp;authorid=2227948" rel="nofollow">[只看他]</a> <strong title="复制帖子链接到剪贴板" style="">5<sup>#</sup> </strong></p> 
    </div> <p></p> <span></span> 
    <div> 
     <div></div> 
     <div></div> 
     <div>
       我懵了。。。 
     </div> 
     <div></div> 
     <br> 
     <br> 
     <br> 
    </div> 
    <div style="">
      明日愁来明日忧 
    </div> 
    <div> 
     <p><a href="http://bbs.51cto.com/thread-1157474-1.html" rel="nofollow"><span style="color:rgb(241,11,0); font-family:'microsoft yahei'; font-size:12px">51CTO社区：活动汇总【3个活动正在进行中】</span></a><span style="font-family:''"><span style="color:rgb(254,36,25)"><span style="color:rgb(1,98,244); font-family:'microsoft yahei'; font-size:12px">丨</span></span></span><span style="color:#307f00"><a href="http://bbs.51cto.com/thread-1170219-1.html" rel="nofollow"><span style="color:rgb(63,167,1); font-family:'microsoft yahei'; font-size:12px">#论坛扒点档#，随你造！</span></a></span> </p> 
     <p></p> 
    </div> </td> 
   <td>&nbsp;</td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td> 
    <div style=""> 
     <dl>
       积分 
      <dd>
        2340&nbsp; 
      </dd> 
      <dd>
        当前离线 
      </dd> 注册时间 
      <dd>
        2010-4-8&nbsp; 
      </dd> 最后登录 
      <dd>
        2013-7-17&nbsp; 
      </dd> 
     </dl> 
     <p><a href="http://bbs.51cto.com/space-uid-1449562.html" rel="nofollow">论坛详细资料</a></p> 
    </div> <cite><a href="http://home.51cto.com/index.php?s=/space/1449562" rel="nofollow">流年伤风 </a>&nbsp;<img align="absmiddle" src="http://bbs.51cto.com/images/forum/arrow.gif" alt=""> </cite> 
    <div> 
     <img src="http://ucenter.51cto.com/avatar.php?uid=1449562&amp;size=middle" alt=""> 
    </div> <p>高级工程师 <img alt="Rank: 7" src="http://bbs.51cto.com/images/default/star_level3.gif"><img alt="Rank: 7" src="http://bbs.51cto.com/images/default/star_level2.gif"><img alt="Rank: 7" src="http://bbs.51cto.com/images/default/star_level1.gif"></p> 
    <dl>
      帖子 
     <dd> 
      <a href="http://home.51cto.com/bbs/get-user-threads?uid=1449562" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">2253</a>&nbsp; 
     </dd> 精华 
     <dd> 
      <a href="http://bbs.51cto.com/digest.php?authorid=1449562" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">1</a>&nbsp; 
     </dd> 无忧币 
     <dd style="color:rgb(102,102,102)"> 
      <a href="http://home.51cto.com/index.php?s=/Account/credit" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">3025 </a> 
     </dd> 
    </dl> <p><a href="http://bbs.51cto.com/medal/index.php?uid=1449562" rel="nofollow"><img width="30" title="信赖用户" alt="29_small.gif" src="http://bbs.51cto.com/medal/medals/29_small.gif"></a><a href="http://bbs.51cto.com/medal/index.php?uid=1449562" rel="nofollow"><img width="30" title="生肖（蛇）" alt="65_small.gif" src="http://bbs.51cto.com/medal/medals/65_small.gif"></a><a href="http://bbs.51cto.com/medal/index.php?uid=1449562" rel="nofollow"><img width="30" title="星座（天蝎座）" alt="79_small.gif" src="http://bbs.51cto.com/medal/medals/79_small.gif"></a><a href="http://bbs.51cto.com/medal/index.php?uid=1449562" rel="nofollow"><img width="30" title="推动者" alt="108_small.gif" src="http://bbs.51cto.com/medal/medals/108_small.gif"></a></p> 
    <ul> 
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     <li><a href="http://blog.51cto.com/blog.php?uid=1449562" rel="nofollow">他的博客</a> </li> 
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     <li style="width:100px"><a href="http://edu.51cto.com/user/user_id-1449562.html?edu_recommend_adid=103" rel="nofollow">他的课程中心</a></li> 
    </ul> </td> 
   <td align="center"> 
    <div></div> 
    <div> 
     <p>发表于&nbsp;2011-4-8 22:58&nbsp;|&nbsp;来自&nbsp; <a title="" href="http://bbs.51cto.com/" rel="nofollow"> 51CTO网页</a> </p> 
     <p><a href="http://bbs.51cto.com/viewthread.php?tid=821402&amp;page=1&amp;authorid=1449562" rel="nofollow">[只看他]</a> <strong title="复制帖子链接到剪贴板" style="">6<sup>#</sup> </strong></p> 
    </div> <p></p> <span></span> 
    <div> 
     <div></div> 
     <div></div> 
     <div>
       ICMP具体端口号？ 
      <br> PING还要问你是什么端口？ 
      <br> 什么公司啊？这等面试。。。 
     </div> 
     <div></div> 
     <br> 
     <br> 
     <br> 
    </div> 
    <div style="">
      好好学习，天天向上！ 
    </div> 
    <div> 
     <p></p> 
     <p></p> 
    </div> </td> 
   <td>&nbsp;</td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td> 
    <div style=""> 
     <dl>
       积分 
      <dd>
        213&nbsp; 
      </dd> 
      <dd>
        当前离线 
      </dd> 注册时间 
      <dd>
        2011-3-7&nbsp; 
      </dd> 最后登录 
      <dd>
        2011-10-26&nbsp; 
      </dd> 
     </dl> 
     <p><a href="http://bbs.51cto.com/space-uid-2816269.html" rel="nofollow">论坛详细资料</a></p> 
    </div> <cite><a href="http://home.51cto.com/index.php?s=/space/2816269" rel="nofollow">水易寒雪 </a>&nbsp;<img align="absmiddle" src="http://bbs.51cto.com/images/forum/arrow.gif" alt=""> </cite> 
    <div> 
     <img src="http://ucenter.51cto.com/avatar.php?uid=2816269&amp;size=middle" alt=""> 
    </div> <p>助理工程师 <img alt="Rank: 3" src="http://bbs.51cto.com/images/default/star_level2.gif"><img alt="Rank: 3" src="http://bbs.51cto.com/images/default/star_level1.gif"></p> 
    <dl>
      帖子 
     <dd> 
      <a href="http://home.51cto.com/bbs/get-user-threads?uid=2816269" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">204</a>&nbsp; 
     </dd> 精华 
     <dd> 
      <a href="http://bbs.51cto.com/digest.php?authorid=2816269" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">0</a>&nbsp; 
     </dd> 无忧币 
     <dd style="color:rgb(102,102,102)"> 
      <a href="http://home.51cto.com/index.php?s=/Account/credit" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">20 </a> 
     </dd> 
    </dl> <p></p> 
    <ul> 
     <li><a href="http://home.51cto.com/space?uid=2816269" rel="nofollow">个人空间</a></li> 
     <li><a href="http://home.51cto.com/index.php?s=/Notify/write/uid/2816269" rel="nofollow">发短消息</a></li> 
     <li><a href="http://home.51cto.com/index.php?s=/space/2816269" rel="nofollow">家园好友</a></li> 
     <li><a href="http://blog.51cto.com/blog.php?uid=2816269" rel="nofollow">他的博客</a> </li> 
     <li><a href="http://down.51cto.com/2816269" rel="nofollow">他的资源</a></li> 
     <li style="width:100px"><a href="http://edu.51cto.com/user/user_id-2816269.html?edu_recommend_adid=103" rel="nofollow">他的课程中心</a></li> 
    </ul> </td> 
   <td align="center"> 
    <div></div> 
    <div> 
     <p>发表于&nbsp;2011-4-9 14:10&nbsp;|&nbsp;来自&nbsp; <a title="" href="http://bbs.51cto.com/" rel="nofollow"> 51CTO网页</a> </p> 
     <p><a href="http://bbs.51cto.com/viewthread.php?tid=821402&amp;page=1&amp;authorid=2816269" rel="nofollow">[只看他]</a> <strong title="复制帖子链接到剪贴板" style="">8<sup>#</sup> </strong></p> 
    </div> <p></p> <span></span> 
    <div> 
     <div></div> 
     <div></div> 
     <div>
       我估计是误导你,看看你能不能说出icmp是不用端口的. 
     </div> 
     <div></div> 
     <br> 
     <br> 
     <br> 
    </div> 
    <div> 
     <p></p> 
     <p></p> 
    </div> </td> 
   <td>&nbsp;</td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td> 
    <div style=""> 
     <div> 
      <a href="http://wpa.qq.com/msgrd?V=1&amp;Uin=33199002&amp;Site=51CTO技术论坛_中国领先的IT技术社区&amp;Menu=yes" rel="nofollow"><img alt="QQ" src="http://bbs.51cto.com/images/default/qq.gif"></a> 
     </div> 
     <dl>
       积分 
      <dd>
        186&nbsp; 
      </dd> 
      <dd>
        当前在线 
      </dd> 注册时间 
      <dd>
        2009-9-1&nbsp; 
      </dd> 最后登录 
      <dd>
        2016-11-14&nbsp; 
      </dd> 
     </dl> 
     <p><a href="http://bbs.51cto.com/space-uid-922715.html" rel="nofollow">论坛详细资料</a></p> 
    </div> <cite><a href="http://home.51cto.com/index.php?s=/space/922715" rel="nofollow">yangye1985 </a>&nbsp;<img align="absmiddle" src="http://bbs.51cto.com/images/forum/arrow.gif" alt=""> </cite> 
    <div> 
     <img src="http://ucenter.51cto.com/avatar.php?uid=922715&amp;size=middle" alt=""> 
    </div> <p>技术员 <img alt="Rank: 2" src="http://bbs.51cto.com/images/default/star_level2.gif"></p> 
    <dl>
      帖子 
     <dd> 
      <a href="http://home.51cto.com/bbs/get-user-threads?uid=922715" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">180</a>&nbsp; 
     </dd> 精华 
     <dd> 
      <a href="http://bbs.51cto.com/digest.php?authorid=922715" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">0</a>&nbsp; 
     </dd> 无忧币 
     <dd style="color:rgb(102,102,102)"> 
      <a href="http://home.51cto.com/index.php?s=/Account/credit" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">674 </a> 
     </dd> 
    </dl> <p><a href="http://bbs.51cto.com/medal/index.php?uid=922715" rel="nofollow"><img width="30" title="信赖用户" alt="29_small.gif" src="http://bbs.51cto.com/medal/medals/29_small.gif"></a><a href="http://bbs.51cto.com/medal/index.php?uid=922715" rel="nofollow"><img width="30" title="生肖（牛）" alt="60_small.gif" src="http://bbs.51cto.com/medal/medals/60_small.gif"></a></p> 
    <ul> 
     <li><a href="http://home.51cto.com/space?uid=922715" rel="nofollow">个人空间</a></li> 
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     <li><a href="http://blog.51cto.com/blog.php?uid=922715" rel="nofollow">他的博客</a> </li> 
     <li><a href="http://down.51cto.com/922715" rel="nofollow">他的资源</a></li> 
     <li style="width:100px"><a href="http://edu.51cto.com/user/user_id-922715.html?edu_recommend_adid=103" rel="nofollow">他的课程中心</a></li> 
    </ul> </td> 
   <td align="center"> 
    <div></div> 
    <div> 
     <p>发表于&nbsp;2011-4-9 14:26&nbsp;|&nbsp;来自&nbsp; <a title="" href="http://bbs.51cto.com/" rel="nofollow"> 51CTO网页</a> </p> 
     <p><a href="http://bbs.51cto.com/viewthread.php?tid=821402&amp;page=1&amp;authorid=922715" rel="nofollow">[只看他]</a> <strong title="复制帖子链接到剪贴板" style="">9<sup>#</sup> </strong></p> 
    </div> <p></p> <span></span> 
    <div> 
     <div></div> 
     <div></div> 
     <div>
       1.首先查本地arp cache信息，看是否有对方的mac地址和IP地址映射条目记录 
      <br> 2.如果没有，则发起一个arp请求广播包，等待对方告知具体的mac地址 
      <br> 3.收到arp响应包之后，获得某个IP对应的具体mac地址，有了物理地址之后才可以开始通信了,同时对ip-mac地址做一个本地cache 
      <br> 4.发出icmp echo request包，收到icmp&nbsp;&nbsp;echo reply包 
      <br> 往往很多人都忽略了上面3步，只知道有最后一步。 
     </div> 
     <div></div> 
     <br> 
     <br> 
     <br> 
    </div> 
    <div> 
     <p></p> 
     <p></p> 
    </div> </td> 
   <td>&nbsp;</td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td> 
    <div style=""> 
     <dl>
       积分 
      <dd>
        840&nbsp; 
      </dd> 
      <dd>
        当前离线 
      </dd> 注册时间 
      <dd>
        2009-9-23&nbsp; 
      </dd> 最后登录 
      <dd>
        2014-10-14&nbsp; 
      </dd> 
     </dl> 
     <p><a href="http://bbs.51cto.com/space-uid-951735.html" rel="nofollow">论坛详细资料</a></p> 
    </div> <cite><a href="http://home.51cto.com/index.php?s=/space/951735" rel="nofollow">fd084 </a>&nbsp;<img align="absmiddle" src="http://bbs.51cto.com/images/forum/arrow.gif" alt=""> </cite> 
    <div> 
     <img src="http://ucenter.51cto.com/avatar.php?uid=951735&amp;size=middle" alt=""> 
    </div> <p>中级工程师 <img alt="Rank: 6" src="http://bbs.51cto.com/images/default/star_level3.gif"><img alt="Rank: 6" src="http://bbs.51cto.com/images/default/star_level2.gif"></p> 
    <dl>
      帖子 
     <dd> 
      <a href="http://home.51cto.com/bbs/get-user-threads?uid=951735" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">794</a>&nbsp; 
     </dd> 精华 
     <dd> 
      <a href="http://bbs.51cto.com/digest.php?authorid=951735" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">1</a>&nbsp; 
     </dd> 无忧币 
     <dd style="color:rgb(102,102,102)"> 
      <a href="http://home.51cto.com/index.php?s=/Account/credit" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">2682 </a> 
     </dd> 
    </dl> <p><a href="http://bbs.51cto.com/medal/index.php?uid=951735" rel="nofollow"><img width="30" title="信赖用户" alt="29_small.gif" src="http://bbs.51cto.com/medal/medals/29_small.gif"></a><a href="http://bbs.51cto.com/medal/index.php?uid=951735" rel="nofollow"><img width="30" title="生肖（猴）" alt="68_small.gif" src="http://bbs.51cto.com/medal/medals/68_small.gif"></a><a href="http://bbs.51cto.com/medal/index.php?uid=951735" rel="nofollow"><img width="30" title="推动者" alt="108_small.gif" src="http://bbs.51cto.com/medal/medals/108_small.gif"></a></p> 
    <ul> 
     <li><a href="http://home.51cto.com/space?uid=951735" rel="nofollow">个人空间</a></li> 
     <li><a href="http://home.51cto.com/index.php?s=/Notify/write/uid/951735" rel="nofollow">发短消息</a></li> 
     <li><a href="http://home.51cto.com/index.php?s=/space/951735" rel="nofollow">家园好友</a></li> 
     <li><a href="http://blog.51cto.com/blog.php?uid=951735" rel="nofollow">他的博客</a> </li> 
     <li><a href="http://down.51cto.com/951735" rel="nofollow">他的资源</a></li> 
     <li style="width:100px"><a href="http://edu.51cto.com/user/user_id-951735.html?edu_recommend_adid=103" rel="nofollow">他的课程中心</a></li> 
    </ul> </td> 
   <td align="center"> 
    <div></div> 
    <div> 
     <p>发表于&nbsp;2011-4-15 00:31&nbsp;|&nbsp;来自&nbsp; <a title="" href="http://bbs.51cto.com/" rel="nofollow"> 51CTO网页</a> </p> 
     <p><a href="http://bbs.51cto.com/viewthread.php?tid=821402&amp;page=1&amp;authorid=951735" rel="nofollow">[只看他]</a> <strong title="复制帖子链接到剪贴板" style="">10<sup>#</sup> </strong></p> 
    </div> <p></p> <span></span> 
    <div> 
     <div></div> 
     <div></div> 
     <div>
       花生解释很到位 
     </div> 
     <div></div> 
     <br> 
     <br> 
     <br> 
    </div> 
    <div> 
     <p></p> 
     <p></p> 
    </div> </td> 
   <td>&nbsp;</td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td> 
    <div style=""> 
     <dl>
       积分 
      <dd>
        257&nbsp; 
      </dd> 
      <dd>
        当前离线 
      </dd> 注册时间 
      <dd>
        2007-6-30&nbsp; 
      </dd> 最后登录 
      <dd>
        2016-4-17&nbsp; 
      </dd> 
     </dl> 
     <p><a href="http://bbs.51cto.com/space-uid-191863.html" rel="nofollow">论坛详细资料</a></p> 
    </div> <cite><a href="http://home.51cto.com/index.php?s=/space/191863" rel="nofollow">zhanjianxin </a>&nbsp;<img align="absmiddle" src="http://bbs.51cto.com/images/forum/arrow.gif" alt=""> </cite> 
    <div> 
     <img src="http://ucenter.51cto.com/avatar.php?uid=191863&amp;size=middle" alt=""> 
    </div> <p>助理工程师 <img alt="Rank: 3" src="http://bbs.51cto.com/images/default/star_level2.gif"><img alt="Rank: 3" src="http://bbs.51cto.com/images/default/star_level1.gif"></p> 
    <dl>
      帖子 
     <dd> 
      <a href="http://home.51cto.com/bbs/get-user-threads?uid=191863" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">204</a>&nbsp; 
     </dd> 精华 
     <dd> 
      <a href="http://bbs.51cto.com/digest.php?authorid=191863" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">0</a>&nbsp; 
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     <dd style="color:rgb(102,102,102)"> 
      <a href="http://home.51cto.com/index.php?s=/Account/credit" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">908 </a> 
     </dd> 
    </dl> <p><a href="http://bbs.51cto.com/medal/index.php?uid=191863" rel="nofollow"><img width="30" title="信赖用户" alt="29_small.gif" src="http://bbs.51cto.com/medal/medals/29_small.gif"></a><a href="http://bbs.51cto.com/medal/index.php?uid=191863" rel="nofollow"><img width="30" title="生肖（牛）" alt="60_small.gif" src="http://bbs.51cto.com/medal/medals/60_small.gif"></a><a href="http://bbs.51cto.com/medal/index.php?uid=191863" rel="nofollow"><img width="30" title="星座（射手座）" alt="80_small.gif" src="http://bbs.51cto.com/medal/medals/80_small.gif"></a><a href="http://bbs.51cto.com/medal/index.php?uid=191863" rel="nofollow"><img width="30" title="评论达人" alt="105_small.gif" src="http://bbs.51cto.com/medal/medals/105_small.gif"></a><a href="http://bbs.51cto.com/medal/index.php?uid=191863" rel="nofollow"><img width="30" title="推动者" alt="108_small.gif" src="http://bbs.51cto.com/medal/medals/108_small.gif"></a><br> </p> 
    <ul> 
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    <div></div> 
    <div> 
     <p>发表于&nbsp;2011-4-15 10:31&nbsp;|&nbsp;来自&nbsp; <a title="" href="http://bbs.51cto.com/" rel="nofollow"> 51CTO网页</a> </p> 
     <p><a href="http://bbs.51cto.com/viewthread.php?tid=821402&amp;page=1&amp;authorid=191863" rel="nofollow">[只看他]</a> <strong title="复制帖子链接到剪贴板" style="">11<sup>#</sup> </strong></p> 
    </div> <p></p> <span></span> 
    <div> 
     <div></div> 
     <div></div> 
     <div>
       简而言之 icmp -》控制协议 -》没有端口号 
     </div> 
     <div></div> 
     <br> 
     <br> 
     <br> 
    </div> 
    <div> 
     <p></p> 
     <p></p> 
    </div> </td> 
   <td>&nbsp;</td> 
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</table>

<table> 
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   <td> 
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       积分 
      <dd>
        3&nbsp; 
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      <dd>
        当前离线 
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      <a href="http://home.51cto.com/index.php?s=/Account/credit" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">6 </a> 
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    <div></div> 
    <div> 
     <p>发表于&nbsp;2011-4-21 16:31&nbsp;|&nbsp;来自&nbsp; <a title="" href="http://bbs.51cto.com/" rel="nofollow"> 51CTO网页</a> </p> 
     <p><a href="http://bbs.51cto.com/viewthread.php?tid=821402&amp;page=1&amp;authorid=3003194" rel="nofollow">[只看他]</a> <strong title="复制帖子链接到剪贴板" style="">12<sup>#</sup> </strong></p> 
    </div> <p></p> <span></span> 
    <div> 
     <div></div> 
     <div></div> 
     <div>
       确实很到位 
     </div> 
     <div></div> 
     <br> 
     <br> 
     <br> 
    </div> 
    <div> 
     <p></p> 
     <p></p> 
    </div> </td> 
   <td>&nbsp;</td> 
  </tr> 
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</table>

<table> 
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       积分 
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        14605&nbsp; 
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        2006-6-15&nbsp; 
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     <p><a href="http://bbs.51cto.com/space-uid-23357.html" rel="nofollow">论坛详细资料</a></p> 
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      <a href="http://bbs.51cto.com/digest.php?authorid=23357" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">11</a>&nbsp; 
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      <a href="http://home.51cto.com/index.php?s=/Account/credit" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">14914 </a> 
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    <div></div> 
    <div> 
     <p>发表于&nbsp;2011-4-21 16:51&nbsp;|&nbsp;来自&nbsp; <a title="" href="http://bbs.51cto.com/" rel="nofollow"> 51CTO网页</a> </p> 
     <p><a href="http://bbs.51cto.com/viewthread.php?tid=821402&amp;page=1&amp;authorid=23357" rel="nofollow">[只看他]</a> <strong title="复制帖子链接到剪贴板" style="">13<sup>#</sup> </strong></p> 
    </div> <p></p> <span></span> 
    <div> 
     <div></div> 
     <div></div> 
     <div>
       Echo Request和Reply（类型8和0）： 
      <br> 　　允许Echo Request消息出站以便于内部用户能够PING一个远程主机。阻止入站Echo Request和出站Echo Reply可以防止外部网络的主机对内部网络进行扫描。如果您使用了位于外部网络的监视器来监视内部网络，就应该只允许来自于特定外部IP的Echo Request进入您的网络。限制ICMP Echo包的大小可以防止“Ping Floods”攻击，并且可以阻止那些利用Echo Request和Reply来“偷运”数据通过防火墙的木马程序。 
      <br> Destination unreachable （类型3）： 
      <br> 　　允许其入站以便于内部网用户可以使用traceroute。需要注意的是，有些攻击者可以使用它来进行针对会话的DoS攻击，如果您曾经历过类似的攻击，也可以阻止它。阻止出站的ICMP Destination unreachable消息，因为它可能会泄漏内部网络的结构。不过有一个例外，对于那些允许外部网络通过TCP访问的内部主机（如位于DMZ区的Web 服务器）发出的Destination unreachable，则应该允许它通过。为了能够支持“Path MTU Discovery”，您应该允许出站的“Packet Too Big”消息（类型3，代码4）到达那些主机。 
      <br> Source quench（类型4）： 
      <br> 　　阻止其入站，因为它可以作为一种DoS攻击，能够降低发送者的发送速度。允许其出站以便于内部主机能够控制发送端发送数据的速度。有些防火墙会忽略所有直接发送到防火墙端口的Source Quench消息，以防止针对于防火墙的DoS攻击。 
      <br> Redirect（类型5，9，10）： 
      <br> 　　Redirect、Router announcement、 Router selection（类型5，9，10）：这些消息都存在潜在危险，因为它们可以用来把数据重定向到攻击者的机器。这些消息都应该被阻止。 
      <br> TTL exceeded（类型11）： 
      <br> 　　允许其进站以便于内部用户可以使用traceroute。“firewalking”使用很低的TTL值来对网络进行扫描，甚至可以通过防火墙对内网进行扫描，所以应该禁止其出站。一些防火墙可以阻止TTL值小于设定值的数据包进入防火墙。 
      <br> Parameter problem（类型12）： 
      <br> 　　禁止其入站和出站。通过使用一个能够进行数据包一致性检查的防火墙，错误和恶意的数据包都会被阻塞。 
     </div> 
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     <br> 
     <br> 
     <br> 
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    <div style="">
      ♥ 
     <span style="color:blue"><a href="http://edu.51cto.com/lecturer/index/user_id-23357.html" rel="nofollow">【大侠唐在飞出品网络教学视频课程 】</a> </span> 
     <br> 天下风云出我辈， 一入江湖岁月催。当年的“小侠唐在飞” 如今变成了“大侠唐在飞”。♫金杯银杯，不如网友的口碑；金奖银奖，不如网友的褒奖；熊掌鸭掌，不如网友的鼓掌~&nbsp; &nbsp; 
     <br> ☺欢迎加入“唐志强技术教学交流群”，群号：67182271。♥ 
     <a href="http://weibo.com/xiaoxiatang" rel="nofollow">【欢迎大家关注 我的新浪微博 http://weibo.com/xiaoxiatang】</a> 
    </div> 
    <div> 
     <p></p> 
     <p></p> 
    </div> </td> 
   <td>&nbsp;</td> 
  </tr> 
 </tbody> 
</table>

<table> 
 <tbody> 
  <tr> 
   <td> 
    <div style=""> 
     <dl>
       积分 
      <dd>
        14605&nbsp; 
      </dd> 
      <dd>
        当前在线 
      </dd> 注册时间 
      <dd>
        2006-6-15&nbsp; 
      </dd> 最后登录 
      <dd>
        2016-11-13&nbsp; 
      </dd> 
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     <p><a href="http://bbs.51cto.com/space-uid-23357.html" rel="nofollow">论坛详细资料</a></p> 
    </div> <cite><a href="http://home.51cto.com/index.php?s=/space/23357" rel="nofollow">小侠唐在飞 </a>&nbsp;<img align="absmiddle" src="http://bbs.51cto.com/images/forum/arrow.gif" alt=""> </cite> 
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    </div> <p>超级版主 <img alt="Rank: 18" src="http://bbs.51cto.com/images/default/star_level3.gif"><img alt="Rank: 18" src="http://bbs.51cto.com/images/default/star_level3.gif"><img alt="Rank: 18" src="http://bbs.51cto.com/images/default/star_level3.gif"><img alt="Rank: 18" src="http://bbs.51cto.com/images/default/star_level3.gif"><img alt="Rank: 18" src="http://bbs.51cto.com/images/default/star_level2.gif"></p> <p>白袍大法师</p> 
    <dl>
      帖子 
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      <a href="http://home.51cto.com/bbs/get-user-threads?uid=23357" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">13434</a>&nbsp; 
     </dd> 精华 
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      <a href="http://bbs.51cto.com/digest.php?authorid=23357" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">11</a>&nbsp; 
     </dd> 无忧币 
     <dd style="color:rgb(102,102,102)"> 
      <a href="http://home.51cto.com/index.php?s=/Account/credit" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">14914 </a> 
     </dd> 
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    <div> 
     <p>发表于&nbsp;2011-4-21 16:54&nbsp;|&nbsp;来自&nbsp; <a title="" href="http://bbs.51cto.com/" rel="nofollow"> 51CTO网页</a> </p> 
     <p><a href="http://bbs.51cto.com/viewthread.php?tid=821402&amp;page=1&amp;authorid=23357" rel="nofollow">[只看他]</a> <strong title="复制帖子链接到剪贴板" style="">14<sup>#</sup> </strong></p> 
    </div> <p></p> <span></span> 
    <div> 
     <div></div> 
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     <div>
       我补充一下，传输层常用的是三元素和五元素 
      <br> 三元素指本机服务提供的三要求： 
      <br> 协议、本机地址、本机端口 
      <br> 
      <br> 五元素是指两个应用连接的五元素： 
      <br> 协议、本地地址、本地端口、远程地址、远程端口。 
      <br> 
      <br> ICMP在网络层协议，不是用端口来说的，它的功能用类型来区别。 
      <br> 
      <br> 
      <br> 这个问题，我们去年就在论坛讨论过。你当时要是。现在也不会。。嗯。。 
      <br> 
      <br> &nbsp;&nbsp;In: 192.168.2.118/19955 --&gt; 192.168.158.138/1;icmp, 
      <br> 这是防火墙上抓出来的 
      <br> 
      <br> 
     </div> 
     <div> 
      <dl> 
       <img alt="" src="http://bbs.51cto.com/images/attachicons/image.gif"> 
       <a href="http://bbs.51cto.com/attachment.php?aid=197880&amp;k=ab71ea7139111717fe2159257e4a001c&amp;t=1479101215&amp;nothumb=yes" rel="nofollow"> 未命名.jpg</a> 
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       <dd> 
        <p>2011-4-21 17:03 </p> 
        <p><img width="720" alt="未命名.jpg" src="http://s3.51cto.com/wyfs02/M01/34/0A/wKioL1OqmTHT-ZVTAALG1wvQFhY121.jpg" style=""> </p> 
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       本帖最后由 小侠唐在飞 于 2014-1-31 12:58 编辑 
     </div> 
    </div> 
    <div style="">
      ♥ 
     <span style="color:blue"><a href="http://edu.51cto.com/lecturer/index/user_id-23357.html" rel="nofollow">【大侠唐在飞出品网络教学视频课程 】</a> </span> 
     <br> 天下风云出我辈， 一入江湖岁月催。当年的“小侠唐在飞” 如今变成了“大侠唐在飞”。♫金杯银杯，不如网友的口碑；金奖银奖，不如网友的褒奖；熊掌鸭掌，不如网友的鼓掌~&nbsp; &nbsp; 
     <br> ☺欢迎加入“唐志强技术教学交流群”，群号：67182271。♥ 
     <a href="http://weibo.com/xiaoxiatang" rel="nofollow">【欢迎大家关注 我的新浪微博 http://weibo.com/xiaoxiatang】</a> 
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   <td> 
    <div style=""> 
     <dl>
       积分 
      <dd>
        325&nbsp; 
      </dd> 
      <dd>
        当前离线 
      </dd> 注册时间 
      <dd>
        2008-10-25&nbsp; 
      </dd> 最后登录 
      <dd>
        2016-9-1&nbsp; 
      </dd> 
     </dl> 
     <p><a href="http://bbs.51cto.com/space-uid-515042.html" rel="nofollow">论坛详细资料</a></p> 
    </div> <cite><a href="http://home.51cto.com/index.php?s=/space/515042" rel="nofollow">yecheng257 </a>&nbsp;<img align="absmiddle" src="http://bbs.51cto.com/images/forum/arrow.gif" alt=""> </cite> 
    <div> 
     <img src="http://ucenter.51cto.com/avatar.php?uid=515042&amp;size=middle" alt=""> 
    </div> <p>助理工程师 <img alt="Rank: 3" src="http://bbs.51cto.com/images/default/star_level2.gif"><img alt="Rank: 3" src="http://bbs.51cto.com/images/default/star_level1.gif"></p> 
    <dl>
      帖子 
     <dd> 
      <a href="http://home.51cto.com/bbs/get-user-threads?uid=515042" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">203</a>&nbsp; 
     </dd> 精华 
     <dd> 
      <a href="http://bbs.51cto.com/digest.php?authorid=515042" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">0</a>&nbsp; 
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      <a href="http://home.51cto.com/index.php?s=/Account/credit" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">1076 </a> 
     </dd> 
    </dl> <p></p> 
    <ul> 
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    </ul> </td> 
   <td align="center"> 
    <div></div> 
    <div> 
     <p>发表于&nbsp;2011-4-21 18:47&nbsp;|&nbsp;来自&nbsp; <a title="" href="http://bbs.51cto.com/" rel="nofollow"> 51CTO网页</a> </p> 
     <p><a href="http://bbs.51cto.com/viewthread.php?tid=821402&amp;page=1&amp;authorid=515042" rel="nofollow">[只看他]</a> <strong title="复制帖子链接到剪贴板" style="">15<sup>#</sup> </strong></p> 
    </div> <p></p> <span></span> 
    <div> 
     <div></div> 
     <div></div> 
     <div>
       好好学习:) 
     </div> 
     <div></div> 
     <br> 
     <br> 
     <br> 
    </div> 
    <div> 
     <p></p> 
     <p></p> 
    </div> </td> 
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</table>

<table> 
 <tbody> 
  <tr> 
   <td> 
    <div style=""> 
     <dl>
       积分 
      <dd>
        1564&nbsp; 
      </dd> 
      <dd>
        当前离线 
      </dd> 注册时间 
      <dd>
        2009-11-21&nbsp; 
      </dd> 最后登录 
      <dd>
        2016-10-10&nbsp; 
      </dd> 
     </dl> 
     <p><a href="http://bbs.51cto.com/space-uid-1042175.html" rel="nofollow">论坛详细资料</a></p> 
    </div> <cite><a href="http://home.51cto.com/index.php?s=/space/1042175" rel="nofollow">cperhero </a>&nbsp;<img align="absmiddle" src="http://bbs.51cto.com/images/forum/arrow.gif" alt=""> </cite> 
    <div> 
     <img src="http://ucenter.51cto.com/avatar.php?uid=1042175&amp;size=middle" alt=""> 
    </div> <p>中级工程师 <img alt="Rank: 6" src="http://bbs.51cto.com/images/default/star_level3.gif"><img alt="Rank: 6" src="http://bbs.51cto.com/images/default/star_level2.gif"></p> 
    <dl>
      帖子 
     <dd> 
      <a href="http://home.51cto.com/bbs/get-user-threads?uid=1042175" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">1518</a>&nbsp; 
     </dd> 精华 
     <dd> 
      <a href="http://bbs.51cto.com/digest.php?authorid=1042175" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">0</a>&nbsp; 
     </dd> 无忧币 
     <dd style="color:rgb(102,102,102)"> 
      <a href="http://home.51cto.com/index.php?s=/Account/credit" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">683 </a> 
     </dd> 
    </dl> <p><a href="http://bbs.51cto.com/medal/index.php?uid=1042175" rel="nofollow"><img width="30" title="信赖用户" alt="29_small.gif" src="http://bbs.51cto.com/medal/medals/29_small.gif"></a><a href="http://bbs.51cto.com/medal/index.php?uid=1042175" rel="nofollow"><img width="30" title="生肖（兔）" alt="62_small.gif" src="http://bbs.51cto.com/medal/medals/62_small.gif"></a><a href="http://bbs.51cto.com/medal/index.php?uid=1042175" rel="nofollow"><img width="30" title="星座（双鱼座）" alt="83_small.gif" src="http://bbs.51cto.com/medal/medals/83_small.gif"></a></p> 
    <ul> 
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     <li><a href="http://blog.51cto.com/blog.php?uid=1042175" rel="nofollow">他的博客</a> </li> 
     <li><a href="http://down.51cto.com/1042175" rel="nofollow">他的资源</a></li> 
     <li style="width:100px"><a href="http://edu.51cto.com/user/user_id-1042175.html?edu_recommend_adid=103" rel="nofollow">他的课程中心</a></li> 
    </ul> </td> 
   <td align="center"> 
    <div></div> 
    <div> 
     <p>发表于&nbsp;2011-4-21 21:00&nbsp;|&nbsp;来自&nbsp; <a title="" href="http://bbs.51cto.com/" rel="nofollow"> 51CTO网页</a> </p> 
     <p><a href="http://bbs.51cto.com/viewthread.php?tid=821402&amp;page=1&amp;authorid=1042175" rel="nofollow">[只看他]</a> <strong title="复制帖子链接到剪贴板" style="">16<sup>#</sup> </strong></p> 
    </div> <p></p> <span></span> 
    <div> 
     <div></div> 
     <div></div> 
     <div>
       哈哈&nbsp;&nbsp;，11楼说的我很赞同，这个公司的面试很有意思。 
     </div> 
     <div></div> 
     <br> 
     <br> 
     <br> 
    </div> 
    <div> 
     <p></p> 
     <p></p> 
    </div> </td> 
   <td>&nbsp;</td> 
  </tr> 
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</table>

<table> 
 <tbody> 
  <tr> 
   <td> 
    <div style=""> 
     <dl>
       积分 
      <dd>
        74&nbsp; 
      </dd> 
      <dd>
        当前离线 
      </dd> 注册时间 
      <dd>
        2011-2-22&nbsp; 
      </dd> 最后登录 
      <dd>
        2016-7-24&nbsp; 
      </dd> 
     </dl> 
     <p><a href="http://bbs.51cto.com/space-uid-2763192.html" rel="nofollow">论坛详细资料</a></p> 
    </div> <cite><a href="http://home.51cto.com/index.php?s=/space/2763192" rel="nofollow">ulsai </a>&nbsp;<img align="absmiddle" src="http://bbs.51cto.com/images/forum/arrow.gif" alt=""> </cite> 
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     <img src="http://ucenter.51cto.com/avatar.php?uid=2763192&amp;size=middle" alt=""> 
    </div> <p>新新人类 <img alt="Rank: 1" src="http://bbs.51cto.com/images/default/star_level1.gif"></p> 
    <dl>
      帖子 
     <dd> 
      <a href="http://home.51cto.com/bbs/get-user-threads?uid=2763192" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">70</a>&nbsp; 
     </dd> 精华 
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      <a href="http://bbs.51cto.com/digest.php?authorid=2763192" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">0</a>&nbsp; 
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      <a href="http://home.51cto.com/index.php?s=/Account/credit" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">20 </a> 
     </dd> 
    </dl> <p><a href="http://bbs.51cto.com/medal/index.php?uid=2763192" rel="nofollow"><img width="30" title="信赖用户" alt="29_small.gif" src="http://bbs.51cto.com/medal/medals/29_small.gif"></a><a href="http://bbs.51cto.com/medal/index.php?uid=2763192" rel="nofollow"><img width="30" title="生肖（蛇）" alt="65_small.gif" src="http://bbs.51cto.com/medal/medals/65_small.gif"></a><a href="http://bbs.51cto.com/medal/index.php?uid=2763192" rel="nofollow"><img width="30" title="星座（天蝎座）" alt="79_small.gif" src="http://bbs.51cto.com/medal/medals/79_small.gif"></a><a href="http://bbs.51cto.com/medal/index.php?uid=2763192" rel="nofollow"><img width="30" title="推动者" alt="108_small.gif" src="http://bbs.51cto.com/medal/medals/108_small.gif"></a></p> 
    <ul> 
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     <li><a href="http://blog.51cto.com/blog.php?uid=2763192" rel="nofollow">他的博客</a> </li> 
     <li><a href="http://down.51cto.com/2763192" rel="nofollow">他的资源</a></li> 
     <li style="width:100px"><a href="http://edu.51cto.com/user/user_id-2763192.html?edu_recommend_adid=103" rel="nofollow">他的课程中心</a></li> 
    </ul> </td> 
   <td align="center"> 
    <div></div> 
    <div> 
     <p>发表于&nbsp;2011-4-21 21:50&nbsp;|&nbsp;来自&nbsp; <a title="" href="http://bbs.51cto.com/" rel="nofollow"> 51CTO网页</a> </p> 
     <p><a href="http://bbs.51cto.com/viewthread.php?tid=821402&amp;page=1&amp;authorid=2763192" rel="nofollow">[只看他]</a> <strong title="复制帖子链接到剪贴板" style="">17<sup>#</sup> </strong></p> 
    </div> <p></p> <span></span> 
    <div> 
     <div></div> 
     <div></div> 
     <div>
       神马HR ，一时间，会说不知道。。 
     </div> 
     <div></div> 
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    </div> 
    <div> 
     <p></p> 
     <p></p> 
    </div> </td> 
   <td>&nbsp;</td> 
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</table>

<table> 
 <tbody> 
  <tr> 
   <td> 
    <div style=""> 
     <div> 
      <a href="http://wpa.qq.com/msgrd?V=1&amp;Uin=372422201&amp;Site=51CTO技术论坛_中国领先的IT技术社区&amp;Menu=yes" rel="nofollow"><img alt="QQ" src="http://bbs.51cto.com/images/default/qq.gif"></a> 
     </div> 
     <dl>
       积分 
      <dd>
        1013&nbsp; 
      </dd> 
      <dd>
        当前在线 
      </dd> 注册时间 
      <dd>
        2007-3-23&nbsp; 
      </dd> 最后登录 
      <dd>
        2016-11-13&nbsp; 
      </dd> 
     </dl> 
     <p><a href="http://bbs.51cto.com/space-uid-134664.html" rel="nofollow">论坛详细资料</a></p> 
    </div> <cite><a href="http://home.51cto.com/index.php?s=/space/134664" rel="nofollow">typuc </a>&nbsp;<img align="absmiddle" src="http://bbs.51cto.com/images/forum/arrow.gif" alt=""> </cite> 
    <div> 
     <img src="http://ucenter.51cto.com/avatar.php?uid=134664&amp;size=middle" alt=""> 
    </div> <p>中级工程师 <img alt="Rank: 6" src="http://bbs.51cto.com/images/default/star_level3.gif"><img alt="Rank: 6" src="http://bbs.51cto.com/images/default/star_level2.gif"></p> 
    <dl>
      帖子 
     <dd> 
      <a href="http://home.51cto.com/bbs/get-user-threads?uid=134664" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">999</a>&nbsp; 
     </dd> 精华 
     <dd> 
      <a href="http://bbs.51cto.com/digest.php?authorid=134664" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">0</a>&nbsp; 
     </dd> 无忧币 
     <dd style="color:rgb(102,102,102)"> 
      <a href="http://home.51cto.com/index.php?s=/Account/credit" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">6322 </a> 
     </dd> 
    </dl> <p></p> 
    <ul> 
     <li><a href="http://home.51cto.com/space?uid=134664" rel="nofollow">个人空间</a></li> 
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     <li><a href="http://home.51cto.com/index.php?s=/space/134664" rel="nofollow">家园好友</a></li> 
     <li><a href="http://blog.51cto.com/blog.php?uid=134664" rel="nofollow">他的博客</a> </li> 
     <li><a href="http://down.51cto.com/134664" rel="nofollow">他的资源</a></li> 
     <li style="width:100px"><a href="http://edu.51cto.com/user/user_id-134664.html?edu_recommend_adid=103" rel="nofollow">他的课程中心</a></li> 
    </ul> </td> 
   <td align="center"> 
    <div></div> 
    <div> 
     <p>发表于&nbsp;2011-4-22 09:36&nbsp;|&nbsp;来自&nbsp; <a title="" href="http://bbs.51cto.com/" rel="nofollow"> 51CTO网页</a> </p> 
     <p><a href="http://bbs.51cto.com/viewthread.php?tid=821402&amp;page=1&amp;authorid=134664" rel="nofollow">[只看他]</a> <strong title="复制帖子链接到剪贴板" style="">18<sup>#</sup> </strong></p> 
    </div> <p></p> <span></span> 
    <div> 
     <div></div> 
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     <div>
       icmp 有协议号的 协议号:1 tcp 6 udp 17 
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</table>

<table> 
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  <tr> 
   <td> 
    <div style=""> 
     <dl>
       积分 
      <dd>
        62&nbsp; 
      </dd> 
      <dd>
        当前离线 
      </dd> 注册时间 
      <dd>
        2008-9-10&nbsp; 
      </dd> 最后登录 
      <dd>
        2012-9-17&nbsp; 
      </dd> 
     </dl> 
     <p><a href="http://bbs.51cto.com/space-uid-475095.html" rel="nofollow">论坛详细资料</a></p> 
    </div> <cite><a href="http://home.51cto.com/index.php?s=/space/475095" rel="nofollow">agustou </a>&nbsp;<img align="absmiddle" src="http://bbs.51cto.com/images/forum/arrow.gif" alt=""> </cite> 
    <div> 
     <img src="http://ucenter.51cto.com/avatar.php?uid=475095&amp;size=middle" alt=""> 
    </div> <p>新新人类 <img alt="Rank: 1" src="http://bbs.51cto.com/images/default/star_level1.gif"></p> 
    <dl>
      帖子 
     <dd> 
      <a href="http://home.51cto.com/bbs/get-user-threads?uid=475095" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">53</a>&nbsp; 
     </dd> 精华 
     <dd> 
      <a href="http://bbs.51cto.com/digest.php?authorid=475095" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">0</a>&nbsp; 
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      <a href="http://home.51cto.com/index.php?s=/Account/credit" style="color:rgb(51,102,153); text-decoration:underline" rel="nofollow">20 </a> 
     </dd> 
    </dl> <p></p> 
    <ul> 
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     <li style="width:100px"><a href="http://edu.51cto.com/user/user_id-475095.html?edu_recommend_adid=103" rel="nofollow">他的课程中心</a></li> 
    </ul> </td> 
   <td align="center"> 
    <div></div> 
    <div> 
     <p>发表于&nbsp;2011-4-22 09:39&nbsp;|&nbsp;来自&nbsp; <a title="" href="http://bbs.51cto.com/" rel="nofollow"> 51CTO网页</a> </p> 
     <p><a href="http://bbs.51cto.com/viewthread.php?tid=821402&amp;page=1&amp;authorid=475095" rel="nofollow">[只看他]</a> <strong title="复制帖子链接到剪贴板" style="">19<sup>#</sup> </strong></p> 
    </div> <p></p> <span></span> 
    <div> 
     <div></div> 
     <div></div> 
     <div>
       这个公司感觉有点问题 
      <br> 应该不是故意考LZ，而是面试的那个人自己本身不懂 
     </div> 
     <div></div> 
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   <td>&nbsp;</td> 
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</table>

<table> 
 <tbody> 
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   <td> 
    <div style=""> 
     <div> 
      <a href="http://wpa.qq.com/msgrd?V=1&amp;Uin=254411810&amp;Site=51CTO技术论坛_中国领先的IT技术社区&amp;Menu=yes" rel="nofollow"><img alt="QQ" src="http://bbs.51cto.com/images/default/qq.gif"></a> 
     </div> 
     <dl>
       积分 
      <dd>
        1759&nbsp; 
      </dd> 
      <dd>
        当前在线 
      </dd> 注册时间 
      <dd>
        2008-4-19&nbsp; 
      </dd> 最后登录 
      <dd>
        2016-8-15&nbsp; 
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     <p>发表于&nbsp;2011-4-22 10:13&nbsp;|&nbsp;来自&nbsp; <a title="" href="http://bbs.51cto.com/" rel="nofollow"> 51CTO网页</a> </p> 
     <p><a href="http://bbs.51cto.com/viewthread.php?tid=821402&amp;page=1&amp;authorid=364634" rel="nofollow">[只看他]</a> <strong title="复制帖子链接到剪贴板" style="">20<sup>#</sup> </strong></p> 
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     <div>
       要么是在故意考你 要么是这个面试官自己什么也不懂个点皮毛装B 
      <br> icmp是不用端口的&nbsp;&nbsp;ping 同样不用端口用的是icmp 协议 
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