单项选择题
A. EIGRP can be used only as the PE-CE routing protocol if the PE and CE routers are in the same AS
B. Other EIGRP AS routes are automatically advertised to the CE router and do not require a redistribution configuration command to be configured
C. Unlike other routing protocols that are used between PE and CE routers, EIGRP supports backdoor links
D. Configure of the VPN is only required on the PE router
单项选择题 The router SIS-R has been configured in a CIS network. As a network administrator, you were required to enable MPLS on that router. Which of the following description is making sense on the basis of the output information?（）
单项选择题 Which of these tools should you use to compress VoIP packets on a low-speed Frame Replay circuit?（）
单项选择题 Which version of NTP was the first to support cryptographic authentication?（）