Cisco CCNP Service Provider 350-501 Question # 17 Topic 2 Discussion

In the given scenario, the goal is to restrict users on the network between R1 and R2 from accessing the external network through R5, while still allowing them access to all resources within the administrative domain. The correct approach is to configure an Access Control List (ACL) that permits traffic to all internal networks and denies traffic to any external address. This ACL should be applied to the R2 interface that connects to R1 in the ingress direction. By doing so, traffic originating from users between R1 and R2 destined for external networks will be blocked, while internal traffic will be allowed.

References: This explanation is derived from the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) study materials, which cover the configuration and application of ACLs in a service provider network environment.