TestKing.com is configuring the serial interface of a Cisco router to connect to the router of a new ISP. A full T1 is being used for the Internet connection. After issuing the show interface serial 0/0 command, it is observed that the interface is UP and the line protocol is DOWN.<br /> Which of the following commands could fix this problem?()<p> TestKing.com is configuring the serial interface of a Cisco router to connect to the router of a new ISP. A full T1 is being used for the Internet connection. After issuing the show interface serial 0/0 command, it is observed that the interface is UP and the line protocol is DOWN.<br /> Which of the following commands could fix this problem?()</p>
A、A. Border# copy running-config startup-config
B、B. Border(config)# no shutdown
C、C. Border(config-if)# encapsulation ppp
D、D. Border(config-if)# no cdp enable
E、E. Border(config-if)# ip routing