We have three routers:
Provider AS1 is advertising a prefix eg: 126.96.36.199/28 to R1 & R2. Due to path selection, R2 is preferring the route to the prefix via R1due to the iBGP having a higher preference.
To get around this a route map is being used on R1 & R2 to prefer it’s own eBGP routes:
route-map ImportRoutesSIP permit 10 set local-preference 250 set weight 200
Traffic flows from R3 to R2 as it has selected the route as its preferred route as it has two iBGP links to either router. However, all routers are in different datacenters, R1 and R3 are both in the same City, R1 & R3 are 208 miles away from R2.
What is the best way to get R3 to prefer prefixes of the same length from R1 over R2? Using WEIGHT would prefer all routes no matter what their AS length is, which is not preferred. So is there a cost we can apply as we do in OSPF?