61 You are configuring an 802.1Q trunk between a Layer 2 switch and a firewall. You read in the documentation that the best way to set up a trunk is to set the port as dynamic desirable. The trunk is not coming up. Which one of these options would be a valid explanation?

使用802.1Q的trunk链路连接2层交换机和防火墙。 你阅读文档， 最好的trunk模式是 “dynamic desirable” 。但是trunk没有开启，哪个选项能解决问题？

A. The firewall does not support Cisco Discovery Protocol. You should set the switchport trunk

mode ON. B. The firewall does not support Cisco Discovery Protocol. You should set the switchport trunk mode to OFF. C. The firewall does not support Cisco Discovery Protocol. You should set the switchport trunk mode as auto. D. The firewall does not support DTP. You should set the switchport trunk mode to ON.

防火墙没有启用DTP，所以你需要将交换机的trunk模式调整为”on”

Answer: D

62. Refer to the exhibit. You are setting up a 2-gigabit EtherChannel. Following IEEE standards, the exhibit shows your configuration in a local switch1. However, EtherChannel is not coming up. Which one of these statements could be a possible reason?

如图所示，你要设置一个2G带宽的以太通道。使用IEEE标准，图中是交换机1的配置。然而 以太通道不能启动，下面哪一个是最可能的原因？

A. EtherChannel is only available in Cisco equipment. B. The customer side is supposed to be running PAgP, which is a Cisco standard. C. PAgP is not an IEEE standard. VRRP should be used. D. The configuration on switch1 needs to be modified to use LACP.

在交换机1 需要使用“LACP”模式来封装以太通道

Answer: D

63. Refer to the exhibit. R2 and R3 are routers connected using Ethernet services from a service provider and can receive pings from each other. OSPF is configured as the routing protocol but adjacency is not happening. According to the output of the show commands in the exhibit, what could be the most likely cause of the problem?

如图所示，R2和R3是使用同一条线路的路由器，一个在用户一个在运行商。他们可以互相 ping通，但是OSPF 邻居不能建立，根据show 出的配置，最有可能是什么原因？

A. Ethernet interfaces were configured as point-to-point. B. Process IDs are not matching. C. Configured bandwidths do not match on both interfaces. D. Broadcasts and multicast are not being propagated over the Ethernet services.

以太服务不允许发送广播和多播

E. OSPF cost does not match on both interfaces.

Answer: D

64. You have a router running BGP for the MPLS network and OSPF for the local LAN network at the sales office. A route is being learned from the MPLS network that also exists on the OSPF local network. It is important that the router chooses the local LAN route being learned from the downstream switch running OSPF rather than the upstream BGP neighbor. Also, if the local OSPF route goes away, the BGP route needs to be used. What should be configured to make sure that the router will choose the LAN network as the preferred path?

有一个路由器在MPLS上运行BGP协议， 在销售办公室内部网络上使用OSPF协议。 一条路由 信息从MPLS网络学习来也同时存在于OSPF内部网络。重要的是路由器会选择BGP的路由， 而不是选择通过OSPF学习来的路由。此外如果OSPF路由消失，BGP路由还是需要使用。应 该怎么做保证这个路由器作为网络首选路由器。

A. static route needs to be added B. floating static route needs to be added C. bgp backdoor command D. ospf backdoor command

 Answer: C
 

65. In BGP routing, what does the rule of synchronization mean?

使用bgp backdoor命令（把EBGP变成IBGP）

在BGP路由协议中，同步是什么意思？

A. A BGP router can only advertise an EBGP learned route, provided that the route is an IGP

route in the routing table. B. A BGP router can only advertise an IBGP learned route, provided that the route is an IGP route in the routing table.

一个BGP 路由器学习只要能从IGP协议到达的所有IBGP邻居通告的路由

C. A BGP router can only advertise an IBGP learned route, provided that the route is an IGP route that is not in the routing table. D. A BGP router can only advertise an EBGP learned route, provided that the route is a metric of 0 in the BGP table.

Answer: B