Comprehensive and Detailed In-Depth Explanation:
This question is based on MPLS (Multiprotocol Label Switching) and its interaction with routing protocols. The goal is to ensure PC1 (10.1.1.1) can communicate with PC2 (10.3.3.1) over MPLS. Let ' s analyze each option carefully.
1️⃣ Understanding MPLS Routing Requirements
To forward traffic using MPLS and LDP, we need:
Loopback interfaces advertised in OSPF to establish LDP neighbor relationships.
Consistent MPLS LDP enablement on all links in the MPLS domain.
End-to-end IP reachability between loopbacks (since LDP uses the loopback for label distribution).
2️⃣ Option A (Correct Answer) Analysis
This configuration enables OSPF on all routers (R1, R2, and R3) across the MPLS domain:
✅ All networks are advertised in OSPF area 0, ensuring IP reachability.
✅ Loopback interfaces (1.1.1.1, 2.2.2.2, 3.3.3.3) are included, which is required for MPLS LDP peer establishment.
✅ PC1 ' s network (10.1.1.0/24) and PC2 ' s network (10.3.3.0/24) are properly advertised, ensuring end-to-end connectivity.
✅ R1, R2, and R3 have OSPF neighbor relationships, meaning LDP can use OSPF routes for label switching.
???? Conclusion: Option A meets all MPLS forwarding requirements and is the correct answer.
3️⃣ Why Other Options Are Incorrect
???? Option B (Incorrect)
Uses BGP instead of OSPF, which is not optimal for MPLS forwarding in a simple MPLS domain.
LDP requires an IGP like OSPF or IS-IS to work efficiently.
BGP alone does not establish LDP label bindings between R1, R2, and R3.
???? Option C (Incorrect)
Mixes OSPF and BGP, causing routing inconsistency.
Uses ip ip-prefix and recursive lookup, which is unnecessary in a standard MPLS domain.
BGP does not distribute labels dynamically like an IGP with LDP.
???? Option D (Incorrect)
R1 does not advertise the 10.1.1.0/24 network, meaning PC1’s network is not reachable.
R3 does not advertise the 10.3.3.0/24 network, meaning PC2’s network is not reachable.
Missing essential routing entries for full end-to-end reachability.
[References:, ✅ HCIP-Datacom Advanced Routing & Switching Technology✅ Huawei Official MPLS and LDP Configuration Guide✅ Huawei Enterprise Networking Documentation, , , , ]
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