Cisco CCNP Service Provider 350-501 Question # 23 Topic 3 Discussion

The absence of routes learned by PE4 from PE5 in other PE routers’ routing tables is likely due to missing route target configurations. Route targets are crucial for importing and exporting VPN routes between VRFs in MPLS Layer 3 VPNs.

Option D is correct because advertising the route targets for PE5 to the other PEs will allow them to import routes from PE5 into their respective VRFs, facilitating communication across the Layer 3 VPN.

References :=

Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) source book and study guide.