Pass the Huawei HCIP-Datacom H12-831_V1.0 Questions and answers with CertsForce

The exhibit shows that R1 and R2 use the same IPv4 subnet, 192.168.1.0/24, on separate LAN interfaces. Because these interfaces belong to different Layer 2 segments, the attached PCs cannot communicate directly despite using the same subnet.

Disabling OSPF on R1 ' s GE0/0/1 does not remove its connected 192.168.1.0/24 route. R1 therefore continues treating destinations such as 192.168.1.2 as directly reachable through that interface, making option A false.

If GE0/0/1 fails, however, the connected route is removed. Assuming R2 advertises its LAN prefix into OSPF, R1 can install the route learned through R2 over the inter-router link.

Under that assumption, R1 can reach 192.168.1.2 and 192.168.1.12.

Therefore, B, C, and D are the intended answers. The OSPF advertisement assumption is essential because the exhibit alone does not show the complete protocol configuration.

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The option lettering in the supplied question is malformed. In the standard option order, the source-IP statement is option B, and it is the item that was not added for IS-IS IPv6.

Unlike OSPFv3, IS-IS operates directly over the data-link layer rather than being encapsulated in IPv4 or IPv6. Consequently, an IS-IS Hello PDU does not have an IP header or an IP source address that could be changed to an IPv6 link-local address.

To support IPv6 route processing, IS-IS was extended with the following information:

TLV 232 — IPv6 Interface Address: Carries one or more 128-bit IPv6 interface addresses.

TLV 236 — IPv6 Reachability: Carries IPv6 prefixes, metrics and reachability attributes.

IPv6 NLPID: The value 142 (0x8E) identifies IPv6 as a supported network-layer protocol and is carried when IPv6 reachability is advertised.

Therefore, TLV 232, TLV 236 and the IPv6 NLPID are valid IS-IS IPv6 extensions. Changing an IS-IS Hello packet’s source IP address is not one of them. Huawei IS-IS documentation

Comprehensive and Detailed In-Depth Explanation:

MPLS packet forwarding is based on label information stored in the LFIB (Label Forwarding Information Base).

The role of different tables in MPLS:✅ RIB (Routing Information Base): Stores routing information, but does not handle MPLS label forwarding.✅ LIB (Label Information Base): Stores label bindings but is used for control-plane operations.✅ FIB (Forwarding Information Base): Used for IP forwarding, not MPLS forwarding.✅ LFIB (Label Forwarding Information Base): The correct table, which maps incoming labels to outgoing labels (or actions like swap, push, pop) and is used for actual MPLS packet forwarding.

???? Reference: HCIP-Datacom Advanced Routing & Switching Technology – MPLS LFIB and Label Forwarding

Route Targets (RTs) are BGP extended communities that control the import and export of VPNv4 routes between VPN instances.

A PE exports routes with its configured Export RT (ERT). A receiving PE imports those routes only when the advertised RT matches one of its Import RTs (IRTs).

In option A, PE1 and PE2 use different RTs, preventing direct route exchange. PE3 imports and exports both RTs, enabling communication with both sites.

In option C, PE1 and PE2 export RT 200:1 and import RT 100:1. PE3 exports RT 100:1 and imports RT 200:1. This creates communication between PE3 and both spokes without allowing direct communication between the spokes.

Options B and D permit route exchange between PE1 and PE2.

Therefore, A and C satisfy the requirements.

HCIP-Datacom-Advanced Routing & Switching Technology V1.0 Training Material.pdf

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VLAN aggregation and MUX VLAN provide different networking functions and use distinct VLAN roles.

VLAN aggregation combines multiple sub-VLANs under a super-VLAN. The sub-VLANs share the IP subnet and default gateway of the super-VLAN, reducing IP address consumption.

MUX VLAN controls Layer 2 communication using principal, group, and separate VLANs. It allows administrators to restrict communication among hosts while maintaining access to designated resources.

However, Huawei ' s MUX VLAN configuration requirements explicitly prohibit using the VLAN ID of a principal VLAN as a super-VLAN or sub-VLAN.

Consequently, an administrator cannot assign the same VLAN ID simultaneously to a super-VLAN and the principal MUX VLAN.

Separate VLAN identifiers must be allocated for the relevant VLAN functions to avoid configuration conflicts.

Therefore, the statement is FALSE.

HCIP-Datacom-Advanced Routing & Switching Technology V1.0 Training Material.pdf

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Comprehensive and Detailed In-Depth Explanation:

Step 1: Understanding OSPF Areas and Summarization

Loopback0 on R5 has IP 10.0.5.5/32 and is advertised into OSPF.

The abr-summary 10.0.5.0 255.255.255.0 command is applied in area 2 on R1, which means:

Instead of advertising individual host routes (like 10.0.5.5/32), R1 advertises the summarized route 10.0.5.0/24 into Area 0 (Backbone).

This summarized route is then propagated into other areas via Area 0 (Backbone).

Step 2: Analyzing the Routing Table of Each Router

R5 (Originating Router in Area 2)

R5 only knows 10.0.5.5/32 because it ' s the originating router.

The abr-summary command does not affect R5 itself.

❌ R5 does not have 10.0.5.0/24.

R1 (ABR for Area 2, Summarizing the Route)

R1 creates and advertises 10.0.5.0/24 into Area 0.

This summary route is sent to other areas via Area 0.

R2 (Connected to Area 0 & Area 1)

Since R2 is part of Area 0 (Backbone), it receives 10.0.5.0/24 from R1.

✅ R2 has 10.0.5.0/24 in its routing table.

R3 (Connected to Area 0 & Area 2)

Since R3 is also connected to Area 0, it receives the summary route 10.0.5.0/24 from R1.

✅ R3 has 10.0.5.0/24 in its routing table.

R4 (In Area 1, which is not directly connected to Area 2)

R4 belongs to Area 1, and unless explicitly advertised through inter-area summarization, it will not have 10.0.5.0/24.

Since no specific mention of summary advertisement into Area 1 is made, R4 does not get 10.0.5.0/24.

❌ R4 does not have 10.0.5.0/24.

Final Answer: ✅ R2, R3 (Option B, C)

Comprehensive and Detailed In-Depth Explanation:

Understanding the BGP and IS-IS Network Topology in the Question:

IS-IS Areas:

Area 49.0001 (Level-1 IS-IS): Contains R1, R2, R4, R5.

Area 49.0002 (Level-2 IS-IS): Contains R3, R6.

R2 acts as an ABR (Area Border Router) and redistributes routes between Level-1 and Level-2 using import-route isis level-2 into level-1.

BGP Route Reflection & Peering:

R2 and R5 are Route Reflectors (RRs).

iBGP peering is established among all routers (R1, R2, R3, R4, R5, R6).

R1 and R4 import 192.168.1.0/24 into BGP, meaning this prefix will be advertised to all iBGP peers.

R3 and R6 import 192.168.2.0/24 into BGP, meaning this prefix will also be advertised to all iBGP peers.

Route Distribution Analysis:

A. The route 192.168.2.0/24 in the routing table of R4 has two next hops. ✅ (Correct)

R3 and R6 import 192.168.2.0/24 into BGP.

R2 and R5 (Route Reflectors) learn this route and reflect it to their clients (R1, R3, R4, R6).

R4 receives two valid paths to 192.168.2.0/24 via R2 and R5 (both iBGP peers).

Since both routes have the same BGP attributes and cost, they are installed as equal-cost paths in R4 ' s routing table.

✅ Statement A is correct: The routing table of R4 has two next hops for 192.168.2.0/24.

B. The routing table of R1 contains two equal-cost default routes. ❌ (Incorrect)

In an IS-IS Level-1-2 setup, default routes are usually provided to Level-1 routers from an ABR (like R2).

However, the question does not mention that R1 is receiving two default routes or that it is in an equal-cost multipath (ECMP) scenario.

R1 may have only one default route, depending on route preference and cost.

❌ Statement B is incorrect: The routing table of R1 does not necessarily contain two equal-cost default routes.

C. The routing table of R4 contains two equal-cost default routes. ❌ (Incorrect)

Similar to R1, R4 is also a Level-1 router in IS-IS.

If R4 were receiving default routes from multiple ABRs (R2 and R5), then it could have equal-cost paths.

However, there is no indication that R4 is receiving two default routes in this scenario.

❌ Statement C is incorrect: The routing table of R4 does not necessarily contain two equal-cost default routes.

D. The routing table of R1 contains the route 192.168.2.0/24. ✅ (Correct)

R3 and R6 import 192.168.2.0/24 into BGP.

R2 and R5 (Route Reflectors) reflect this route to their iBGP peers, including R1.

Since R1 is an iBGP client of R2 and R5, it will receive 192.168.2.0/24 and install it in its routing table.

✅ Statement D is correct: The routing table of R1 contains the route 192.168.2.0/24.

Final Conclusion:

✅ A. The route 192.168.2.0/24 in the routing table of R4 has two next hops.

❌ B. The routing table of R1 does not necessarily contain two equal-cost default routes.

❌ C. The routing table of R4 does not necessarily contain two equal-cost default routes.

✅ D. The routing table of R1 contains the route 192.168.2.0/24.

Thus, the correct answers are: A, D.

LSAs and Their Origin Router Associations:

Link-LSA: Origin Router = 10.0.1.1

Intra-Area-Prefix-LSA: Origin Router = 10.0.4.4

Network-LSA: Origin Router = 10.0.3.3

Inter-Area-Prefix-LSA: Origin Router = 10.0.1.1

Bidirectional Forwarding Detection (BFD) rapidly detects forwarding-path failures between network devices. When a single-hop BFD session enters the Down state, troubleshooting should focus on connectivity, session configuration, and BFD packet exchanges.

Checking the local and remote discriminators helps identify configuration mismatches that prevent session establishment. Examining BFD packet statistics helps determine whether control packets are being transmitted and received. Ping testing can identify basic IP connectivity problems.

However, checking whether a static route bound to BFD remains in the routing table is not necessary to diagnose why the BFD session went Down. The route may have been withdrawn as a consequence of the BFD failure.

Therefore, the appropriate answer is C. Huawei ' s BFD troubleshooting procedures prioritize session configuration, packet statistics, and link connectivity.

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