56. The core of a network has four routers connected in a square design with Gigabit Ethernet links using /30 subnets. The network is used to carry voice traffic and other applications. Convergence time is taking more than expected. Which three actions would you take to improve OSPF convergence time? (Choose three.)

一个核心网络，使用千兆线路地址用规划好的/30的子网来连接4台路由器。这个网络是承载 语音和其他服务的。网络的收敛时间非常慢，以下哪三个办法能提高OSPF协议的收敛速度。

A. Increase MTU of the interfaces to accommodate larger OSPF packets. B. Change the network type to point-to-point on those links. 把线路类型改成点到点 C. Reduce SPF initial timer. E. Enable OSPF.

 Answer: BCE

57. Refer to the exhibit. BGP-4 routing to the Internet, in normal behavior, may create asymmetrical routing for different prefixes. The BGP routing table indicates that traffic should follow the paths indicated in the exhibit, but packets are not going further than the border router in AS 4. What could be the cause of this problem?

减少SPF算法的计时器

D. Increase hello interval to avoid adjacency flapping.

开始OSPF协议

如图所示，BGP协议运行在互联网络。在正常情况下，可以会造成不一致的路由前缀。BGP 路由表中应该只有最短路径的，但是在As4的包不能去更远的路由器了。什么问题造成这个 情况？

A. TCP Intercept is configured in AS 4. B. Unicast Reverse Path Forwarding is configured in loose mode in this router. C. Packets may be leaving AS 1 without the BGP routing flag set to 1. D. Unicast Reverse Path Forwarding is configured in strict mode in this router.

单播反向路径转发在路由器上是严格配置的

E. There is a missing Unicast Reverse Path Forwarding configuration.

Answer: D

58. Half of your network uses RIPv2 and the other half runs OSPF. The networks do not communicate with each other. Which two of these factors describe the impact of activating EIGRP over each separate part? (Choose two.)

一个网络一部分使用RIPv2一部分使用OSPF，这两个网络不互相沟通。哪两个选项描述了，

在没有一个区域开始使用EIGRP?

A. EIGRP will not be accepted when configured on the actual RIPv2 routers. B. OSPF will no longer be used in the routing table, because you only have EIGRP internal routes running. OSPF的路由表不再使用了，因为已经运行了EIGRP路由协议 C. OSPF will no longer be used in the routing table, because you only have EIGRP external routes running. D. RIPv2 will populate its RIP database but not its routing table, because you only have EIGRP external routes running. E. RIPv2 will populate its RIP database but not its routing table, because you only have EIGRP internal routes running.

RIPV2的路由将进入数据库，但是不进入路由表，因为EIGRP路由协议已经运行

F. OSPF database will have RIPv2 routes.

 Answer: BE

59. Your company is researching a new application that runs over IPv6, but part of it must still have IPv4 support. Your company uses a traditional IPv4 network. Your plan is not to run IPv6 over the whole network, but to segment parts of the network or even to operate simultaneously with IPv6 and IPv4. You must make a brief presentation about IPv6 technology to the board of technical directors. Which three of these items could be part of your presentation? (Choose three.)

你的公司正在基于IPv6开始一种新的应用程序，但是这个应用必须兼容IPv4。你公司的在使 用IPv4的网络。你计划不用在整个网络都运行IPv6，只用在一部分网络同时运行IPv4和IPv6 你需要对董事会技术部门作出IPv6的技术的简要介绍。以下哪三个是您演示的主要内容。

A. Tunnel IPv6 over IPv4 to connect far-end IPv6 networks.

60. You are deploying two core switches, one in each building, 50 km away from each other. The cross-connection between them will be a Layer 2 2-gigabit EtherChannel with an 802.1Q trunk. You configured it correctly but the link does not come up. The port is in the "admin up" state, and the line protocol is in the "down" state. The fiber link is OK. What would be the most likely reason for the link not to come up?

你正在部署两台核心交换机，在两个相隔50公里的建筑物中。他们中间使用的是2层带宽是 2G的以太通道使用802.1Q的TRUNK.配置是正确的，但是链路没有启动，端口处于管理UP， 协议down的状态。光纤线路的完好的，有什么因素可能造成这个问题？

A. The switches are not the same model. B. You are not using the correct SFP.

你没有使用正确SFP（光端模块）

C. You are not using correct optical media converters. D. Configuration should be modified, because the distance is longer.

Answer: B