LAB: BGP BestPath Selection - Weight

- Using the most influential attribute, configure SW1 so that traffic from AS 300 going to AS 54 prefixes exits towards R3, and that traffic from AS 300 going to AS 254 networks exits towards R6.

 

SW1

router bgp 300
 no synchronization
 bgp log-neighbor-changes
 neighbor 155.1.37.3 remote-as 200
 neighbor 155.1.37.3 route-map FROM_R3 in
 neighbor 155.1.67.6 remote-as 100
 neighbor 155.1.67.6 route-map FROM_R6 in
 neighbor 155.1.79.9 remote-as 300
 no auto-summary
!        
ip as-path access-list 1 permit _54$
ip as-path access-list 2 permit _254$
!
route-map FROM_R3 permit 10
 match as-path 1
 set weight 1000

verification:

Rack1SW1#show ip bgp regexp _54$
BGP table version is 30, local router ID is 150.1.7.7
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 28.119.16.0/24   155.1.37.3                          1000 200 100 54 i
*                   155.1.67.6                             0 100 54 i
*> 28.119.17.0/24   155.1.37.3                          1000 200 100 54 i
*                   155.1.67.6                             0 100 54 i
*> 114.0.0.0        155.1.37.3                          1000 200 100 54 i
*                   155.1.67.6                             0 100 54 i
*> 115.0.0.0        155.1.37.3                          1000 200 100 54 i
*                   155.1.67.6                             0 100 54 i
*> 116.0.0.0        155.1.37.3                          1000 200 100 54 i
*                   155.1.67.6                             0 100 54 i
*> 117.0.0.0        155.1.37.3                          1000 200 100 54 i
*                   155.1.67.6                             0 100 54 i
*> 118.0.0.0        155.1.37.3                          1000 200 100 54 i
*                   155.1.67.6                             0 100 54 i
*> 119.0.0.0        155.1.37.3                          1000 200 100 54 i
*                   155.1.67.6                             0 100 54 i


Rack1SW1#show ip bgp regexp _254$
BGP table version is 30, local router ID is 150.1.7.7
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*  205.90.31.0      155.1.37.3                             0 200 254 ?
*>                  155.1.67.6                          1000 100 200 254 ?
*  220.20.3.0       155.1.37.3                             0 200 254 ?
*>                  155.1.67.6                          1000 100 200 254 ?
*  222.22.2.0       155.1.37.3                             0 200 254 ?
*>                  155.1.67.6                          1000 100 200 254 ?