Let’s break this down step-by-step based on Huawei IS-IS VPN and multi-process behavior.

???? Configuration Summary:

Process 1: IS-IS for the global routing table

Process 2: IS-IS for VPN instance tt

Process 3: IS-IS for VPN instance rr

✅ Option C: Correct

Process 1 contains only global routing information.

The configuration of isis 1 does not include any vpn-instance keyword, meaning it is bound to the global routing table.

It does not interact with VPN routing tables unless explicitly configured with import/export mechanisms or route leaking (which is not shown here).

Huawei Datacom Reference:

“When an IS-IS process is not associated with a VPN instance, it belongs to the global routing table and only maintains global routes.”

(Source: HCIE-Datacom Study Guide v3.0 – Chapter: IS-IS for IPv4 and IPv6, Section: Multi-Instance Routing)

✅ Option D: Correct

Routing information of process 2 is isolated from that of process 3.

isis 2 is bound to VPN instance tt

isis 3 is bound to VPN instance rr

Each IS-IS process in Huawei VRF context maintains independent LSDBs and routing tables, and by default, they do not share routing information unless route leaking or redistribution is configured (which is not shown in the config).

Huawei Datacom Reference:

“IS-IS processes bound to different VPN instances operate independently and do not share routing information.”

(Source: HCIE-Datacom Study Guide v3.0 – Chapter: MPLS L3VPN with IS-IS)