求教一个思科的路由选择问题

ppz1983

<p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">最近在思科教材上看到以下命令输出，有些不解，望各位大侠进来指点一下，不胜感激！！</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">在一台名为</span><span lang="EN-US"><font face="Times New Roman">Cougars</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">的路由器上输入</span><span lang="EN-US"><font face="Times New Roman">show ip route</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">命令后，输出如下</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman">Cougars&gt; <b style="mso-bidi-font-weight: normal;">show ip route<p></p></b></font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman">Code: C – connected, S – static, R – RIP, M – mobile, B – BGP,<span style="mso-spacerun: yes;">&nbsp; </span></font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman">D – EIGRP, EX – EIGRP external, O – <place wst="on"><city wst="on">OSPF</city>, <state wst="on">IA</state></place> – OSPF inter area,<span style="mso-spacerun: yes;">&nbsp; </span></font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman">E1 – OSPF external type 1, E2 – OSPF external type 2, E – EGP,<span style="mso-spacerun: yes;">&nbsp; </span></font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman">I – IS-IS, L1- IS-IS level 1, L2 – IS-IS lever 2,<span style="mso-spacerun: yes;">&nbsp; </span></font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman">* - candidate default</font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><p><font face="Times New Roman">&nbsp;</font></p></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman">Gateway of last resort is not set</font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><p><font face="Times New Roman">&nbsp;</font></p></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman"><span style="mso-spacerun: yes;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>144.253.0.0 is subnetted (mask is 255.255.255.0) ,1 subnets</font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman">C<span style="mso-spacerun: yes;">&nbsp; </span>144.253.100.0<span style="mso-spacerun: yes;">&nbsp; </span>is directly connected.<span style="mso-spacerun: yes;">&nbsp; </span>Ethernet 1</font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman">R<span style="mso-spacerun: yes;">&nbsp; </span>153.50.0.0<span style="mso-spacerun: yes;">&nbsp; </span>[120/1] via 183.8.128.12,<span style="mso-spacerun: yes;">&nbsp; </span>00:00:09, Ethernet 0</font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman"><span style="mso-spacerun: yes;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>183.8.0.0 is subnetted (mask is 255.255.255.128) ,4 subnets</font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman" color="#e61a1a">R<span style="mso-spacerun: yes;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>183.8.0.128<span style="mso-spacerun: yes;">&nbsp; </span>[120/1] via 183.8.128.130,<span style="mso-spacerun: yes;">&nbsp; </span>00:00:17, Serial 0</font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman"><span style="mso-spacerun: yes;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>[120/1] via 183.8.64.130,<span style="mso-spacerun: yes;">&nbsp; </span>00:00:17, Serial 1</font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman" color="#e61a1a">C<span style="mso-spacerun: yes;">&nbsp; </span>183.8.128.0<span style="mso-spacerun: yes;">&nbsp;&nbsp; </span>is directly connected.,<span style="mso-spacerun: yes;">&nbsp; </span>Ethernet 0</font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman">C<span style="mso-spacerun: yes;">&nbsp; </span>183.8.64.128<span style="mso-spacerun: yes;">&nbsp; </span>is directly connected.,<span style="mso-spacerun: yes;">&nbsp; </span>Serial 1</font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US"><font face="Times New Roman" color="#ee1111">C<span style="mso-spacerun: yes;">&nbsp; </span>183.8.128.128<span style="mso-spacerun: yes;">&nbsp;&nbsp; </span>is directly connected.,<span style="mso-spacerun: yes;">&nbsp; </span>Ethernet 0</font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">我的问题是倒数第一和第三行输出：</span><span lang="EN-US"><font face="Times New Roman">183.8.128.0</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">子网段和</span><span lang="EN-US"><font face="Times New Roman">183.8.128.128</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">子网段都是直联的，怎么能从同一个以太网口</span><span lang="EN-US"><font face="Times New Roman">Ethernet 0</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">出去？参考倒数第五行</span><span lang="EN-US"><font face="Times New Roman">183.8.0.128</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">子网通过</span><span lang="EN-US"><font face="Times New Roman">Serial 0</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">下一跳访问，而</span><span lang="EN-US"><font face="Times New Roman">Serial 0</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">的地址</span><span lang="EN-US"><font face="Times New Roman">183.8.128.130</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">是属于</span><span lang="EN-US"><font face="Times New Roman">138.8.128.128</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">子网的，是不是最后一行写错了，应该是</span><span lang="EN-US"><font face="Times New Roman">183.8.128.128<span style="mso-spacerun: yes;">&nbsp;&nbsp; </span>is directly connected.,<span style="mso-spacerun: yes;">&nbsp; </span>Serial 0 </font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">？？？</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;;">请指教！本人水平很菜，若是原则性错误，还望不要取笑！</span></p><p></p>