BGP decision process
1. Weight check, highest
2. Local preference check, highest
3. Local route check.
4. AS path length check, shortest
5. Origin check, lowest, 0, 1, 2
6. MED check, lowest
7. prefer EBGP over IBGP Patch
8. Prefer the path to the closest IBGP neighbor
9. prefer the oldest route for EBGP paths
10. prefer the lowest BGP neighbor ID