There is R1-R2-R3 in AS 100 R1 is peering with R4 which is in AS 200 and R3 is peering with R5 in AS 300. R2 is not running BGP on it. For R3 to reach the routes on R4 we need to redistribute BGP in IGP on R1. But the redistribution is not recommended. Is there any other solution?