Minimal Configuration
297
F I G U R E 8 . 2
BGP path-selection diagram
Is Next-hop
reachable?
No
Ignore route.
Yes
Choose the path
with the highest
Weight.
Are Weights equal?
Choose the biggest
Local Preference.
Yes
Are Local
Preferences equal?
No
Was route originated
by local router?
Choose the
shortest AS Path.
Are AS
Paths equal?
Choose lowest
Origin Code.
Select route.
Are Origin
Codes equal?
Choose the
lowest MED.
Are MEDs equal?
Choose External
over Internal.
Are path
types equal?
Choose closest
IGP neighbor.
Are IGP
neighbors equal?
Choose the path
with the lowest
Router ID.
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
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