In a carrier's MPLS VPN network, what are the outer and inner labels when a client on PE2 accesses a route converted by PE1?

In a carrier's MPLS VPN network, when a client access a route converted by a Provider Edge (PE) router, labels play a crucial role in directing packets through the network. The outer label is used for routing the packet through the provider's core network, while the inner label is specific to the customer's VPN routing and forwarding instance.

The outer label (in this case, 1025) is assigned by the ingress PE router (PE1) when it sends packets into the MPLS network. This label indicates the next hop in the core of the MPLS backbone. It is thus responsible for determining the path the packet will take through the network.

The inner label (1027) represents the actual destination in the context of the customer's VPN. This label is used by the egress PE router (PE2) to determine how to forward the packet to the correct end-user or endpoint within the customer’s VPN.

In your chosen answer, the outer label is correctly identified as 1025, which is utilized for routing through the carrier's backbone, while the inner label of 1027 identifies the specific destination within the client’s VPN. Therefore, this option accurately describes the roles of outer and inner labels in an MPLS VPN scenario.