Study the exhibit carefully. Routers A and B are customer routers. Routers 1， 2， 3 and 4 are provider routers. The routers areoperating with various IOS versions. Which frame mode MPLS configuration statement is true？（）A.Before MPLS is enabled， the ip cef command is only requited on routers 1 and 4B.After MPLS is enabled， the ip cef command is only required on routers 1 and 4C.Before MPLS is enabled， the ip cef command is only required on the Ethernet 0 interfaces ofrouters 1 and 4D.After MPLS is enabled， the ip cef command is only required on the Ethernet 0 interfaces ofrouters 1 and 4E.Before MPLS is enabled， the ip cef command must be applied to all provider routers

单项选择题

Study the exhibit carefully.

Routers A and B are customer routers. Routers 1， 2， 3 and 4 are provider routers. The routers areoperating with various IOS versions. Which frame mode MPLS configuration statement is true？（）

A.Before MPLS is enabled， the ip cef command is only requited on routers 1 and 4
B.After MPLS is enabled， the ip cef command is only required on routers 1 and 4
C.Before MPLS is enabled， the ip cef command is only required on the Ethernet 0 interfaces ofrouters 1 and 4
D.After MPLS is enabled， the ip cef command is only required on the Ethernet 0 interfaces ofrouters 1 and 4
E.Before MPLS is enabled， the ip cef command must be applied to all provider routers

CCNP(642-832)