关于OSPF的hello packets

小熊

怎么理解？？？<br><br>题目问到OSPF hello packets 的ADDRESS ？？？

简单爱

哈哈，懂了。！

小熊

再看这个<br><br>The OSPF routing protocol maintains a topology database of information about other routers in the<br>network.<br>What is a characteristic of this database?<br>A. The Dijkstra algorithm is used to create the topology database.<br>B. All entries listed in the topology database will be included in the routing tables on each router.<br>C. All routers in the same OSPF area will have a unique topology database.<br>D. LSA packets are used to update and maintain the topology database.<br><br>不懂

cwav

原文由 [B]小熊[/B] 发表:<br>再看这个<br><br>The OSPF routing protocol maintains a topology database of information about other routers in the<br>network.<br>What is a characteristic of this database?<br>A. The Dijkstra algorithm is used to create the topology database.<br>B. All entries listed in the topology database will be included in the routing tables on each router.<br>C. All routers in the same OSPF area will have a unique topology database.<br>D. LSA packets are used to update and maintain the topology database.<br><br>不懂<br>

<br>OSPF共有三张表，采用dijkstra的SPF算法，通过发送LSA来更新路由表。拓扑表只存放路由器学习到的目标地址，并选出最佳路径和备用路径；然后从拓扑表中选择最佳路径并存放于路由表中。<br>

cwav

原文由 [B]小熊[/B] 发表:<br>怎么理解？？？<br><br>题目问到OSPF hello packets 的ADDRESS ？？？<br>

<br>题目？

小熊

On point-to-point networks, OSPF hello packets are addresses to which address?<br>A. 127.0.0.1<br>B. 172.16.0.1<br>C. 192.168.0.5<br>D. 223.0.0.1<br>E. 224.0.0.5<br>F. 254.255.255.255.255

简单爱

再加一个问题：Which statements is true regarding the command sequence shown below? (Choose three)<br>RouterA(config)# interface loopback 0<br>RouterA(config-if)# ip address 192.168.31.33 255.255.255.255<br>A. It creates a virtual, software only, interface.<br>B. It uses a wildcard mask of 255.255.255.255.<br>C. It ensures that an interface is always active for OSPF processes.<br>D. It provides a way to test the convergence of OSPF routing updates.<br>E. The mask of 255.255.255.255 is called a host mask.<br>F. These commands can only be issued to configure serial interfaces.<br>对这个loopback的作用有点看不懂？？<br>

cwav

原文由 [B]小熊[/B] 发表:<br>On point-to-point networks, OSPF hello packets are addresses to which address?<br>A. 127.0.0.1<br>B. 172.16.0.1<br>C. 192.168.0.5<br>D. 223.0.0.1<br>E. 224.0.0.5<br>F. 254.255.255.255.255<br>

<br><br>OSPF是一组播的形式发送路由更新包的；）你看看哪个是组播

小熊

224.0.0.5<br><br>^^

cwav

原文由 [B]简单爱[/B] 发表:<br>再加一个问题：Which statements is true regarding the command sequence shown below? (Choose three)<br>RouterA(config)# interface loopback 0<br>RouterA(config-if)# ip address 192.168.31.33 255.255.255.255<br>A. It creates a virtual, software only, interface.<br>B. It uses a wildcard mask of 255.255.255.255.<br>C. It ensures that an interface is always active for OSPF processes.<br>D. It provides a way to test the convergence of OSPF routing updates.<br>E. The mask of 255.255.255.255 is called a host mask.<br>F. These commands can only be issued to configure serial interfaces.<br>对这个loopback的作用有点看不懂？？<br><br>

<br>ADE<br>loopback是一个虚拟接口，也成环回接口……可以作为路由发起源