В статье "Traffic Engineering: Local Routing Policy" описаны несколько методов манипуляции приоритетами отправки трафика через соседние автономные системы, т.е. описано как в BGP переопределять отправку трафик на определенные сети через определенный канал или управлять балансировкой трафика между каналами.
Примеры файлов конфигурации из статьи:
Setting the Local Preference for all routes received from a BGP neighbor
!
router bgp 60055
neighbor 192.0.254.17 remote-as 40077
neighbor 192.0.254.17 route-map ispa-in in
neighbor 219.2.19.1 remote-as 50066
neighbor 219.2.19.1 route-map ispb-in in
!
route-map ispa-in permit 10
set local-preference 90
!
route-map ispb-in permit 10
set local-preference 110
!
Setting the Local Preference depending on AS path
!
ip as-path access-list 4 permit _30088_
ip as-path access-list 4 deny .*
!
route-map ispa-in permit 10
set local-preference 90
!
route-map ispb-in permit 10
match as-path 4
set local-preference 80
!
route-map ispb-in permit 20
set local-preference 110
!
Prepending the AS path
!
ip as-path access-list 4 permit _30088_
ip as-path access-list 4 deny .*
!
route-map ispa-in permit 10
set as-path prepend 60055
!
route-map ispb-in permit 10
match as-path 4
set as-path prepend 60055 60055 60055
!
route-map ispb-in permit 20
!
Using communities to help select the best route
!
router bgp 60055
bgp always-compare-med
!
ip bgp-community new-format
ip community-list 1 permit 50066:3001
ip community-list 1 deny
ip community-list 2 permit 50066:3002
ip community-list 2 deny
!
route-map ispa-in permit 10
set metric 10
!
route-map ispb-in permit 10
match community 1
set metric 10
set local-preference 120
!
route-map ispb-in permit 20
match community 2
set metric 20
!
route-map ispb-in permit 30
set metric 10
!
BGP Load Balancing
!
router bgp 60055
maximum-paths 4
!
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