4517dc03___and_how_to_prepare_for_them___Description
[Step] 7 [Consideration] MED [Description] 
The MED or metric is a path attribute that is communicated from one AS to another; it is used to tell a neighboring AS that a specific entrance point is preferred. The lower the MED the higher that specific path is considered. Networks are not required to pay attention to this attribute (optional).
Top 5 Hardest Topics on the CCNP ROUTE Exam (and how to prepare for them)
Description