1. Make end to end connectivity first. 2. Block the network for these site 1)Make sure that Site 4 will not advertise any network to Site 5 which it receiving from Site3 routers. 2) On site 5 , when we check routing table of R2 router, it don't have network of Site3 routers. ping 147.147.21.1 should be deny and ping 147.147.21.37 should be reachable.
