Huawei H12-831_V1.0 Exam Practice Test Instant Access

Question 1

As shown in the figure, R1 to R4 are four routers in AS123. They all run OSPF to implement route reachability within the AS.

Network segments 10.1.1.0/24 and 10.4.4.0/24 are not advertised into OSPF.

R1 and R4 establish an IBGP peer relationship using Loopback0 and advertise network segments 10.1.1.0/24 and 10.4.4.0/24 into BGP.

Which of the following methods can be used to implement communication between PC1 and PC2?

Options:

ADeploy policy-based routing on R1 and specify R2 as the next hop for traffic from PC1 to PC2.

BDeploy MPLS and LDP on R1 to R4 and establish LSPs for routes 1.1.1.1/32 and 4.4.4.4/32.

CRun BGP on R2 and R3, and establish full-mesh IBGP connections in AS 123.

DOn R1 and R4, import routes 10.1.1.0/24 and 10.4.4.0/24 into OSPF.

Answer : C, D

Comprehensive and Detailed In-Depth

1. Understanding the Routing Issue

R1 and R4 are BGP routers and have an IBGP connection.

R2 and R3 are OSPF-only routers (they do not run BGP).

Networks 10.1.1.0/24 and 10.4.4.0/24 are advertised into BGP but not OSPF.

PC1 (10.1.1.1) and PC2 (10.4.4.1) need communication, but their networks are not known to OSPF routers R2 and R3.

To fix this, we need a method that ensures R2 and R3 learn the routes for 10.1.1.0/24 and 10.4.4.0/24.

2. Evaluating Each Answer Option

Option A: 'Deploy policy-based routing on R1 and specify R2 as the next hop for traffic from PC1 to PC2.'

Incorrect.

Policy-Based Routing (PBR) does not solve the issue of missing routes in OSPF.

Even if R1 forwards traffic to R2, R2 does not know how to reach 10.4.4.0/24, causing packet drops.

A proper routing protocol solution is required instead of PBR.

Option B: 'Deploy MPLS and LDP on R1 to R4 and establish LSPs for routes 1.1.1.1/32 and 4.4.4.4/32.'

Incorrect.

MPLS requires label-switched paths (LSPs) but does not distribute routing information itself.

The real problem is that R2 and R3 do not have routing entries for 10.1.1.0/24 and 10.4.4.0/24.

MPLS does not fix the missing route advertisement issue.

Option C: 'Run BGP on R2 and R3, and establish full-mesh IBGP connections in AS 123.'

Correct.

If R2 and R3 run BGP, they can form IBGP sessions with R1 and R4 and learn routes 10.1.1.0/24 and 10.4.4.0/24 via BGP.

R2 and R3 would then be able to forward traffic correctly between PC1 and PC2.

This is a valid method to fix the issue.

Option D: 'On R1 and R4, import routes 10.1.1.0/24 and 10.4.4.0/24 into OSPF.'

Correct.

By redistributing BGP routes into OSPF, R1 and R4 can ensure that R2 and R3 learn the missing networks (10.1.1.0/24 and 10.4.4.0/24) via OSPF.

This allows full reachability without running BGP on R2 and R3.

This is another valid method to fix the issue.

Final Answer:

C and D are correct.

HCIP-Datacom-Advanced Routing & Switching Technology Reference:

BGP and OSPF Route Redistribution

IBGP Full-Mesh Requirement and Route Propagation

How Policy-Based Routing Works and Its Limitations

Question 2

If the migration preparation is insufficient, which of the following problems may occur?

Options (Multiple Choice):

AWhen an interface cannot go up but no network cable tester is available, it is difficult to determine whether the interface hardware or cable is faulty.

BThe migration fails, and the configuration file is not backed up. As a result, the service rollback fails.

CA hardware fault occurs on a board, but no spare board is available.

DEngineers cannot arrive at the migration site at the scheduled time.

Answer : A, B, C, D

Comprehensive and Detailed In-Depth

Network migration requires detailed planning to prevent service disruptions and rollback failures.

Potential issues due to poor preparation:

A. No network cable tester available Hard to diagnose whether the issue is hardware or cable-related.

B. No backup of configuration files If migration fails, services cannot be restored quickly.

C. No spare hardware available Hardware failures may cause long service downtimes.

D. Engineers arriving late Delays may lead to extended service downtime or missed migration windows.

Reference: HCIP-Datacom Advanced Routing & Switching Technology -- Migration Best Practices

Question 3

In the figure, the company wants to ensure secure communication between the headquarters and branch, and isolate the R&D areas from non-R&D areas, without changing the current network deployment.

To meet this requirement, an administrator deploys BGP/MPLS IP VPN on the network.

Which of the following statements are true?

ATo enable communication between the headquarters and branch R&D areas, both the ERT and IRT of VPN1 and VPN2 can be set to 100:100.

BTo implement communication between the headquarters and branch R&D areas, the RDs of VPN1 and VPN2 need to be set to the same value.

CR&D areas and non-R&D areas have overlapping address spaces. Therefore, services in the two areas cannot be isolated.

DTo isolate R&D areas from non-R&D areas at the headquarters, the RTs of VPN1 can all be set to 100:100 and the RTs of VPN3 can all be set to 200:200.

Answer : A, D

Comprehensive and Detailed In-Depth

To verify the correct answers, let's analyze how BGP/MPLS IP VPN is used for secure communication and isolation in an enterprise network.

1. Understanding BGP/MPLS IP VPN Concepts

MPLS VPN (Multiprotocol Label Switching Virtual Private Network) is used to:

Allow communication between specific sites by using Route Targets (RTs).

Ensure isolation of specific areas (e.g., R&D vs. non-R&D) by controlling RT import/export policies.

Utilize Route Distinguisher (RD) to make overlapping IP addresses unique within the VPN.

2. Analyzing the Answer Choices

A. 'To enable communication between the headquarters and branch R&D areas, both the ERT and IRT of VPN1 and VPN2 can be set to 100:100.' TRUE

ERT (Export Route Target) and IRT (Import Route Target) define which VPNs share routing information.

If VPN1 (HQ R&D) and VPN2 (Branch R&D) use the same RT (100:100), they will exchange routes, enabling communication.

Correct configuration:

VPN1: ERT 100:100, IRT 100:100

VPN2: ERT 100:100, IRT 100:100

This is correct and enables communication between HQ and branch R&D areas.

B. 'To implement communication between the headquarters and branch R&D areas, the RDs of VPN1 and VPN2 need to be set to the same value.' FALSE

RD (Route Distinguisher) is only used to make overlapping IP addresses unique within the MPLS VPN.

RD does NOT control route exchange between VPNs (RTs control route exchange).

VPN1 and VPN2 can have different RDs but still communicate if they share the same RT (100:100).

RDs do NOT need to be the same for VPNs to communicate.

This statement is false.

C. 'R&D areas and non-R&D areas have overlapping address spaces. Therefore, services in the two areas cannot be isolated.' FALSE

Overlapping address spaces are common in MPLS VPNs and can be isolated using unique Route Targets (RTs).

As long as VPNs have different RTs, their traffic remains isolated.

For example:

VPN1 (R&D): RT 100:100

VPN3 (non-R&D): RT 200:200

Even with overlapping IPs, R&D and non-R&D areas are completely isolated.

This statement is false.

D. 'To isolate R&D areas from non-R&D areas at the headquarters, the RTs of VPN1 can all be set to 100:100 and the RTs of VPN3 can all be set to 200:200.' TRUE

Setting different RTs for R&D (100:100) and non-R&D (200:200) ensures complete isolation.

Correct configuration:

VPN1 (R&D): RT 100:100

VPN3 (non-R&D): RT 200:200

Since VPN1 and VPN3 do NOT share the same RTs, their routes remain separate.

This ensures isolation between R&D and non-R&D areas.

Question 4

The path that IP packets pass through on an MPLS network is called a label switched path (LSP). An LSP is a bidirectional path that specifies the transmission direction of data flows.

ATRUE

BFALSE

Answer : B

Question 5

On a PIM-SM multicast network, a network engineer finds that multicast clients cannot receive multicast dat

a. Which of the following is not a possible cause of this problem?

AThe unicast routes from multicast devices to the RP are unavailable.

BThe downstream interfaces of multicast devices do not receive any (*, G) Join messages.

CDownstream interfaces of multicast devices are disabled from forwarding State-Refresh messages.

DThe RP addresses of multicast devices are different.

Answer : C

Question 6

As its network scale expands, an enterprise plans to move scattered servers to the same equipment room for unified management. During hardware migration, network engineers do not need to perform device commissioning and therefore do not need to work out a migration solution.

ATRUE

BFALSE

Answer : B

Question 7

On the network shown in the figure, the DHCP server function is enabled on GE0/0/0 of R2, and the address pool is an interface address pool.

When GE0/0/0 and GE0/0/1 of R1 function as DHCP clients, only one interface can obtain an IP address by default.

Options:

ATRUE

BFALSE

Answer : A

Comprehensive and Detailed In-Depth

Understanding the DHCP Process in This Scenario:

DHCP Server on R2:

The DHCP server is configured on interface GE0/0/0 of R2.

The address pool is an interface address pool, meaning that IP addresses are allocated from the subnet of GE0/0/0 (i.e., 10.0.12.0/24).

DHCP Clients on R1:

Both interfaces (GE0/0/0 and GE0/0/1) on R1 are set as DHCP clients, meaning they will send DHCP DISCOVER messages to obtain an IP address dynamically.

Why Only One Interface Gets an IP Address?

Interface address pools in Huawei devices assign only one IP address per MAC address (which is typically the router's MAC).

Since both interfaces belong to R1, they share the same MAC address when making a DHCP request.

As a result, the DHCP server on R2 only assigns one IP address to the first requesting interface.

The second request is ignored or denied by the DHCP server due to the duplicate MAC address issue.

Key Takeaways:

Huawei routers using an interface-based DHCP address pool assign only one IP per MAC address.

Since both interfaces on R1 have the same MAC, only one gets an IP.

This behavior is expected in Huawei's HCIP-Datacom-certified DHCP configurations.

HCIP-Datacom-Advanced Routing & Switching Technology Reference:

Huawei HCIP-Datacom Official Certification Guide, Chapter on DHCP Server and Client Configurations.

Huawei Datacom Configuration Guide, Section on Interface Address Pools and Address Assignment Limitations.

Huawei Enterprise Networking Training Materials, DHCP Relay and DHCP Server Behavior.

Huawei H12-831_V1.0 HCIP-Datacom-Advanced Routing & Switching Technology V1.0 Exam Practice Test