BGP supports a wide variety of Path Attributes. BGP use these path attributes to examine the competing BGP paths (ROUTES) in BGP table to choose the best path(route).

1. Next Hop - It lists the next-hop IP address used to reach a prefix. If Next hop is reachable? If no route to reach Next Hop, router cannot use this route.
2. WEIGHT - It is a numeric value set by a router when receiving updates to INFLUENCE the route for a prefix. It is not advertised to any BGP peers. Bigger is PREFERRED
3. Local Preference - It is a numeric value set and communicated within a single AS for the purpose of choosing best route for all routers in that AS to reach a certain network. Bigger is preferred
4. Locally injected routes - Locally injected routes (routes injected using network command) are better than iBGP/eBGP learned.
5. AS Path - It is the number of ASNs in the AS Path. Smaller is preferred.
6. Origin - Preferred I over E & E over ?. It implies that the route was injected into BGP as I (IGP), E (EGP) or ? (incomplete information).
7. Multi-Exit Discriminator (MED) - ALLOWS an AS to tell a neighboring AS the best path to forward packets into the first AS. Smaller is preferred.
8. Neighbor type - eBGP is preferred over iBGP.
9. IGP metric - Route with nearest IGP neighbor (lowest IGP metric) is preferred.
10. 10. eBGP route - Oldest (longest known) route is preferred.
11. Neighbor Router ID - Lowest is preferred.
12. Neighbor IP address - Lowest is preferred.

BGP supports a wide variety of Path Attributes. BGP use these path attributes to examine the competing BGP paths (routes) in BGP table to choose the best path(route).