问答题 Drag the protocols that are used to distribute MPLS labels from the above to the target area on thebelow.（Not all options will be used）

问答题 Drag and drop question. The upper gives the MPLS functions， the bottom describes the planes. Drag the above items to the proper location at the below

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？（）