A very common requirement in a multi-homed design is the primary/backup setup where the lower speed (or sometimes lower quality) link should only be used when the primary link fails.
AS-path prepending is configured in Cisco IOS with route-map based per-neighbor outbound filter. The actual prepending is specified within the route-map with the set as-path prepend command.
router bgp 65001
neighbor 10.1.0.2 remote-as 65200
neighbor 10.1.0.2 description Backup ISP
neighbor 10.1.0.2 route-map prepend out
!
route-map prepend permit 10
set as-path prepend 65001 65001 65001
No comments:
Post a Comment