题库精选:CCNA考试自测题第2卷

　　25) When a router receives a packet, it accepts or rejects a packet by examining what (当路由器接受到数据包时，它通过检查什么而决定接受或拒绝数据包)？

　　A. The MAC address of the source of the packet

　　B. The address of the source network/node number

　　C. The address of the destination network/node

　　D. The MAC address of the next router

　　26) Low overhead of a routing algorithm is normally associated with (路由选择算法的低代价通常和什么相关)？

　　A. Optimal route

　　B. CPU usage

　　C. Accuracy

　　D. Converg e n c e

　　27) Convergence is not an issue if (收敛并不会成为一个问题，如果)：

　　A. Routers are added to the network

　　B. Some of the network interfaces are down

　　C. CPU/bandwidth usage of the routers changes

　　D. An invariant network topology is selected for the network architecture

　　28) An Internet Protocol (IP) router selects (网际协议( I P )路由器选择)：

　　A. An entire path from source to destination

　　B. The next route step

　　C. The two adjacent routers to itself

　　D. All of the above.

　　29) IP ROUTE configuration command for a static route includes which of the following　parameters (静态路由的IP ROUTE配置命令包括下列哪一个参数)？
　　
　　A. Subnetwork number of the destination network

　　B. Subnet mask of the source network

　　C. IP address of the interface of the router which the packet should use

　　D. MAC address of the next router on the path

　　30) Given the following portion of the network:

　　Network A→ Router X→ Router Y→ Network B

　　I n t e r f a c e : I n t e r f a c e : 8 6 . 0 . 0 . 0

　　X 0 Y0

　　3 5 . 3 . 3 . 4

　　and assuming a network mask of 255.0.0.0 for both A and B networks, Which one of the

　　following represents a correct command to configure Router X to send data from Network A to Network B (给定网络的下列端口：

　　网络A→路由器X→路由器Y→网络B

　　接口： 接口： 8 6 . 0 . 0 . 0

　　X 0 Y 0

　　3 5 . 3 . 3 . 4

　　并假设A和B网络的网络掩码为2 5 5 . 0 . 0 . 0，则下面的哪一个代表了配置路由器X从网络A向网络B发送数据的正确命令)？

　　A. #IP ROUTE 85.0.0.0 255.0.0.0 35.3.3.3

　　B. #ip route 86.0.0.0 255.0.0.0 35.3.3.4

　　C. #ip route 86.0.0.0 255.0.0.0 35.3.3.3

　　D. #ip route 85.0.0.0 255.0.0.0 35.3.3.4