71. Refer to exhibits 1 and 2. A company uses a Metro Ethernet (Gigabit Ethernet) dedicated circuit to communicate between users (subnet B) and servers (subnet A) as shown in Exhibit 1. Both routers use OSPF to advertise the subnets. During a weekly management meeting, they realize that the WAN link is oversize. They have been using only 2 Mb/s in the worst-case scenario. So they propose a new, cheaper WAN connection using a 2-Mb/s Frame-Relay point-to-point link to interconnect both sites (Exhibit 2). The Frame Relay service provider informs them that multicast traffic is not allowed to run over the service provider network. Which one of these options is best to enable the company to establish the OSPF neighbor adjacency?
如图所示，1和2。在图1中一个公司使用一个专线网络(千兆网络)来连接用户(子网B) 和服务器(子网A)之间，两个路由器使用OSPF宣告子网。在每周的网络会议上，认识到 WAN网络带宽太大了。他们只是使用了2M的带宽。他们想使用一个更为便宜的WAN连接。 如图2是一个2M带宽的帧中继点到点线路。服务商告诉他们在网络中不能使用多播。要建立
OSPF邻居，需要做什么?
A. Use OSPF network broadcast, because it uses unicast to establish a neighbor relationship.
B. Use OSPF network point-to-multipoint, because it uses unicast to establish a neighbor relationship.
C. Use OSPF network point-to-point, because it uses unicast to establish a neighbor relationship.
D. Use OSPF network point-to-multipoint nonbroadcast, because it establishes a neighbor relationship using unicast packets.
OSPF使用网络类型是 点到多点非广播。因为这样建立邻居使用的是单播包
E. Use OSPF network nonbroadcast, because it establishes a neighbor relationship using multicast.
Answer: D
72. 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
73. 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 trunkmode 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
74. 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
75. 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
