BGP best path selection
December 18, 2008 2 Comments
The complexity as well as the efficiency of BGP resides in the concept of “attributes” of routes and the way the protocol juggles them to determine the best path, therefore the need for a “quick guide” to use when dealing with BGP design. I hope the following BGP best path selection diagram will be of help:
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.