What is the correct EBGP path attribute list, ordered from most preferred to least preferred, that the BGP best-path algorithm uses?
What is the correct EBGP path attribute list, ordered from most preferred to least preferred, that the BGP best-path algorithm uses?
The BGP path selection process prioritizes the path attributes in the following order: weight, local preference, AS path, and MED. Weight is entirely local to the router and is the first criterion utilized by BGP to select a path. Local preference is the second attribute considered, determining the preferred path for outbound traffic. The AS path follows, where the shortest path is preferred in inter-AS routing. Finally, the MED attribute is utilized to select routes between autonomous systems.
remember WLAM
Nice way to remember ;)
Very good trick to remember it!!! Thanks mate.
Path Selection Attributes: Weight > Local Preference > Originate > AS Path > Origin > MED > External > IGP Cost > eBGP Peering > Router ID
This pneumonic will help you memorize how BGP selects best route. "We Love Oranges AS Oranges Mean Pure Refreshment!" We === Weight (Highest) Love === LOCAL_PREF (Highest) Oranges === Originate (local) AS === AS_PATH (shortest) Oranges === ORIGIN Code (IGP > EGP > Incomplete) Mean === MED (lowest) Pure === Paths (External > Internal) Refreshments === RID (lowest)
We Love Oranges As Oranges Mean Pure Refreshment
We Love Oranges As Oranges Mean Pure Refreshment Easy acronym to remember order
Given answer is correct
We Love Oranges AS Oranges Mean Pure Refreshment KW
B is correct WLAM
Routing policy is based on the following attributes: Prefer the highest weight attribute (local to router) Prefer the highest local preference attribute (global with AS) Prefer route originated by the local router (next hop = 0.0.0.0) Prefer the shortest AS path (least number of autonomous systems in AS-path attribute) Prefer the lowest origin attribute (IGP < EGP < incomplete) Prefer the lowest MED attribute (exchanged between autonomous systems)
https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13753-25.html#anc2