多项选择题 The Peanut router is able to successfully ping the Serial 0 and Ethernet 0 interface of the Popcorn router, but a ping issued to the Ethernet 1 interface fails. Based on the above output, what are the potential causes of this problem?（）

单项选择题 Which one of the following EIGRP commands can check the IP addresses of the adjacent neighbors, as well as verifying the EIGRP retransmit intervals and queue counts?（）

单项选择题 A new router, named TK1, is being installed. You wish to add this router to your existing OSPF network. In doing so, you configure the following: TK1(config)# router ospf 1 TK1(config-router)# network 10.10.10.0 255.255.255.0 area 0 After making this change, you notice that the networks attached to TK1 are not being learned by the other OSPF routers. What could be the cause of this?（）