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BGP Best Path Selection Algorithm

How is the administrative distance positioned in the bgp route decision ?

i.e If a route is learned from iBGP with higher "local prefernece" and eBGP with lower "local prefernece" - which path will be installed in the routing table

the path learned from eBGP or the path with higer local prefernce ?

1 REPLY
Anonymous
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Re: BGP Best Path Selection Algorithm

For your scenario the path with the higher local pref will be installed in the routing table althogh its ibgp.

if a router recieves the same prefix from 2 neighbors 1 from ibgp and the other from ebgp

the router will compare them with the bgp path selection algorithm

the one that wins will be installed in the routing table with the admin distance of the kind of route it is so if the ibgp route won the path selection you will see in the routing table the admin distance of 200,if the ebgp route won you'll see 20 in the admin distance.

so remember the ibgp/ebgp comparision is the 9th in the path selection algorithm so an ibgp route can win the path selection by (local pref weight....)

and if the ibgp won then you'll see the ibgp admin dstance in your routing tables.

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