BGP best path selection
November 10, 2018 2 Comments
The complexity and the efficiency of BGP reside in the concept of route “attributes” and the way the protocol juggles them to determine the best path.
This is a quick guide (refresh of an old article), still very actual for those dealing with BGP design.
I hope the following Cisco BGP best path selection diagram will be of help:
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CCIE, the beginning! 
Hello,
Great flow chart. It def keep it as a reference. One thing that I would add to this, the decision point right after multipath, where it asks about the eBGP more stable (older route) I think you are missing a check for “bgp bestpath compare-routerid”. With that command the stability check is ignored and eBGP routes are compared based on router-ids.
More info on http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094431.shtml step 10.
Thanks
TK
Hi Tom,
Good point, I added the missing ramification to the flowchart. I appreciate your participation, thank you.