BGP best path selection

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:



Download the pdf version here

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2 Responses to BGP best path selection

  1. Tom Kacprzynski says:

    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 step 10.



    • cciethebeginning says:

      Hi Tom,
      Good point, I added the missing ramification to the flowchart. I appreciate your participation, thank you.

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