Re: Query on BGP path selection

Hi Pratik,,

  I sort of understood your question but not sure fully ,it seems that you
are asking how the 172.16.1.0 subnet which resides in AS 6554(R1 and R2 are
the members) in order to reach to AS 6559 (R3 and R4 are the
members).R1&R3,R2&R4 are directly connected.

Based on the way I understood the definition of the attributes ,the cisco
router would use the BGP bestpath selection algorithm as defined in the
below link to determine the same.

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094431.shtml

Assuming the next-hop is reachable and all the attributes before local
preference are same for both the path,my thinking is,it would take the
R1-R3.Hopefully not misunderstanding your question.

Thanks

Regards
Anantha Subramanian Natarajan

On Sun, Dec 13, 2009 at 11:14 AM, pratik bendke <pratikbendke_at_gmail.com>wrote:

> Hi Frd's
>
> Having query in EBGP the scenario is
>
> eg:-
> R1(local preference 200) ----------------!------------------
> R3(MED 4000) R1-R3 DIRECTLY CONECTED
> !
> AS 6554 !
> AS 6559
> 172.16.1.0 !
> !
> !
> R2(Local preference 100) ----------------!------------------
> R4(MED 0 default) R2-R4 DIRECTLY CONECTED
>
>
> R1 & R2 in same AS 6554
> R3 & R4 in same AS 6559
>
> Now query is ntwork 172.16.1.0 take which path to reach router in AS 6559
>
> Path R1 - R3 ? OR
> Path R2 - R4 ?
>
>
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Received on Tue Dec 15 2009 - 11:02:37 ART