单项选择题
A.Fa0/0 fails
B.The command is rejecteD
C.The existing three neighbors fail
D.The neighborship with 172.16.2.20 fails and then reestablishes
E.None of the other answers is correct
单项选择题 Routers R1 and R2, currently EIGRP neighbors over their Fa0/0 interfaces (respectively),both use EIGRP authentication. Tuesday at 8 p.m. the neighborship fails. Which of the following wo uld not be useful when investigating whether authenticationhad anything to do with the failure？（）
单项选择题 Routers R1 and R2 are EIGRP neighbors using their Fa0/0 interfaces, respectively. An engineer adds the ip hello - interval eigrp 9 6 command to R1s Fa0/0 configuration. Which of the following is true regarding the results from this c hange？（）
单项选择题 Router R1 has working interfaces S0/0, S0/1, and S0/2, with IP address/prefix combinations of 10.10.10.1/24, 10.10.11.2/24, and 10.10.12.3/22. R1s configuration includes the command s router eigrp 9 and network 10.0.0.0. The show ip eigrp interfaces command lists S0/0 and S0/1 in the command output, but not S0/2. Which answer gives the reason for the omission？（）