单项选择题
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？（）
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？（）
