On the BGP/MPLS IP VPN network shown in the figure, which of the following RT...

A PE imports a VPNv4 route only when at least one RT attached to that route matches an Import RT configured in the receiving VPN instance. Bidirectional communication therefore requires reciprocal matching:

Site1/Site2 ERT must match Site3 IRT.

Site3 ERT must match Site1/Site2 IRT.

Evaluation of the displayed configurations:

Option A — Correct: All PEs export and import 100:1. All three sites import one another’s routes, providing full-mesh communication.

Option B — Incorrect: PE1 exports 200:1, but PE3 imports only 100:1; PE3 exports 200:1, but PE1 imports only 100:1. Consequently, Site1 and Site3 cannot exchange routes bidirectionally.

Option C — Correct: Site1 exchanges routes with Site3 through RT 100:1, while Site2 exchanges routes with Site3 through RT 200:1. PE3 imports and exports both RTs. This supports Site1-to-Site3 and Site2-to-Site3 communication while maintaining separate RT groups for Site1 and Site2.

Option D — Correct: PE1 and PE2 export 200:1, which PE3 imports. PE3 exports 100:1, which PE1 and PE2 import. This is a valid hub-and-spoke RT design with Site3 functioning as the hub.

Huawei specifies that one site’s Export RT must match the other site’s Import RT, and the reverse matching must also exist for bidirectional communication. Huawei BGP/MPLS IP VPN configuration guide