bgp selection of routes

jahilnt10 · ‎10-05-2007

I'm receiving routes from my upstream providers..

How bgp selecting best route while I'm receiving routes with default parameters from both upstream providers

sh ip bgp 210.2.184.0

BGP routing table entry for 210.2.184.0/24, version 1658

Paths: (2 available, best #2, table Default-IP-Routing-Table)

Not advertised to any peer

38193 23966

117.20.21.21 from 117.20.21.21 (221.132.112.251)

Origin IGP, localpref 100, valid, external

17557 23966

202.125.147.5 from 202.125.147.5 (202.125.135.39)

Origin IGP, localpref 100, valid, external, best

You see second route is best while attributes are same...what else left which is deciding second route is best..

Collin Clark · ‎10-05-2007

Carefully review http://www.cisco.com/warp/public/459/25.shtml#bestpath

jahilnt10 · ‎10-05-2007

thanks for sharing URL...I fall in #10..

old learned route is getting priorty over new one..

Collin Clark · ‎10-05-2007

Glad it helped.

HTH and please rate.

Mohamed Sobair · ‎10-05-2007

Hi,

at your example, you can just use the AS-Prepending rule and apply it outpound direction to affect your incoming traffic if you want the second ISP to be prefered for specific Prefix.

HTH

Mohamed Sobair