简答题 BGP的Community对于选择最优路径有什么作用？

单项选择题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？（）

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.
E.OSPF cost does not match on both interfaces.

问答题Routers R1， R2， and R3 are configured in a hub and spoke frame relay environment， with router R1 as the hub. You have configured Router R1， Router R2， and Router R3 to run EIGRP over the frame relay connections. No sub-interfaces are used. You have configured a single IP subnet on all the Frame Relay interfaces. Router R1 can reach both router R2 and R3， but R2 and R3 can not reach each other. What is the probable cause of this problem？

单项选择题Refer to the exhibit. Routers A and B are directly connected and running EIGRP，but they are unable to form a neighbor relationship. What is the most likely cause？（）

A.The network statements are misconfigured.
B.The IP address statements are misconfigured.
C.The autonomous system is misconfigured.
D.There is a physical issue with the cable.

单项选择题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？（）

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

单项选择题Refer to the exhibit. Routers A and B are directly connected. Given the configuration, how many EIGRP routes will router B see in its routing table?（）

A.0
B.1
C.2
D.3
E.4