Configure Policy Routing on the Core Routers

Articles » Scalable Policy Routing » Configure Policy Routing on the Core Routers

BGP configuration on the Legacy router changes only slightly: a route-map is attached to the network statement advertising the IP prefixes of the legacy servers:

router bgp 65000
 network 10.0.20.0 mask 255.255.255.0 route-map FRBest
!
route-map FRBest permit 10
 set community 65000:100

The RemoteSite peer policy template is changed on the CoreInet router to set the MED to 200 on all outgoing updates:

router bgp 65000
 template peer-policy RemoteSite
  route-map InetMED out
!
route-map InetMED permit 10
 set metric 200

The changes on the CoreFR router are a bit more extensive:

• An ip community-list is defined to match the target BGP community (65000:100).
• A route-map is used to match BGP prefixes with the target BGP community and change their MED to 100. The MED of all other BGP prefixes is set to 300.
• The RemoteSite peer policy template is modified to include an outgoing route-map.

router bgp 65000
 template peer-policy RemoteSite
  route-map FRMED out
!
ip community-list standard FRBest permit 65000:100
!
route-map FRMED permit 10
 match community FRBest
 set metric 100
!
route-map FRMED permit 20
 set metric 300