多项选择题
Which three of the following steps are mandatory when configuring MPLS on Cisco IOS? （）(Choose three.)
A. start LDP B. enable CEF switching C. configure the MPLS ID D. disable IP TTL propagation E. configure conditional label advertising F. enable label switching on frame mode interfaces
单项选择题 Why is it appropriate to use conditional label advertising when deploying MPLS? （）
单项选择题 When implementing MPLS VPNs between CE and PE routers, which of these statements is correct? （）
单项选择题 Which PIN architecture works with DMVPN, GETVPN, and Ethernet? （）
