Get Huawei H12-831_V1.0 Exam Practice Questions - Real and Updated

Answer : D

Comprehensive and Detailed In-Depth

Understanding the IS-IS Topology in the Questio n:

R1 (Level-1 Router) is connected to R2 (Level-1-2 Router).

R2 connects Level-1 and Level-2 areas, making it an inter-area router.

R3 (Level-2 Router) connects to R2.

The loopback addresses are:

R1: 10.0.1.1/32

R2: 10.0.2.2/32

R3: 10.0.3.3/32

Key Command Used: default-route-advertise always level-1

This command forces R1 to advertise a default route (0.0.0.0/0) to Level-1 routers.

Level-1 routers (like R1) do not have visibility into Level-2 routes unless a default route is provided by an L1-L2 router (R2 in this case).

Analyzing Each Option:

Option A (TRUE):

If R1 pings an unknown address like 10.0.4.4, it will use the default route if available. However, if no such route exists, it will not send any packets.

This behavior is expected, so this statement is true.

Option B (TRUE):

10.0.2.2 (R2) is a Level-1-2 router, and it can communicate with 10.0.3.3 (R3), which is a Level-2 router.

Since R2 and R3 are both in Level-2, they can exchange routes.

So, 10.0.2.2 can ping 10.0.3.3. This statement is true.

Option C (TRUE):

10.0.1.1 (R1) is a Level-1 router, and 10.0.2.2 (R2) is a Level-1-2 router.

Since R2 is Level-1-2, it shares Level-1 routes with R1, allowing communication between R1 (10.0.1.1) and R2 (10.0.2.2).

Therefore, this statement is true.

Option D (FALSE - Correct Answer):

10.0.1.1 (R1) is a Level-1 router, which means it only knows about Level-1 routes.

10.0.3.3 (R3) is a Level-2 router, and its route is only known by Level-2 routers (R2 & R3).

Since Level-1 routers do not learn Level-2 routes directly (unless specific redistribution is done), R1 does not have a route to 10.0.3.3.

Therefore, R1 (10.0.1.1) cannot ping R3 (10.0.3.3), making this statement false.

Conclusion:

The false statement is Option D (10.0.1.1 can ping 10.0.3.3).

HCIP-Datacom-Advanced Routing & Switching Technology V1.0 -- IS-IS Route Types and Forwarding Principles

Huawei Official HCIP-Datacom Study Guide -- IS-IS Level-1 and Level-2 Routing Concepts

Huawei Documentation on default-route-advertise always level-1 Command

Answer : B, D

Answer : A, B

Comprehensive and Detailed In-Depth

1. Understanding Site of Origin (SoO) in MPLS VPNs

SoO (Site of Origin) is used in MPLS VPNs to prevent loops in multi-homed CE scenarios.

Routes with the same SoO value are not advertised back to the same site.

2. Analysis of Each Answer Choice

A . 'To enable CE3 to receive the route, run the command peer 10.1.1.1 soo 200:1 on PE1.' ( False)

SoO is used to prevent loops by tagging routes that belong to the same site.

Applying SoO (200:1) on PE1 for CE1 means that any other PE (such as PE2) receiving the route will not advertise it back to the same site (CE1).

This statement is false because applying SoO here does not directly enable CE3 to receive the route. Instead, CE3 must accept routes with SoO values properly configured.

B . 'If the commands peer 10.1.1.1 soo 200:1 and peer 10.1.2.1 soo 200:1 are run on PE1, CE2 accepts the route.' ( False)

SoO ensures that a route received from one CE is not sent back to another CE in the same site.

If SoO (200:1) is assigned to CE1 and CE2, routes will be blocked because they share the same SoO tag.

Thus, CE2 will not accept the route, making this statement false.

C . 'If the command peer 10.1.3.1 substitute-as is run on PE2, CE3 accepts the route.' ( True)

substitute-as allows a router to replace the received AS number in the AS_PATH with another AS number, ensuring that routes are accepted even when AS_PATH filtering is in place.

This prevents CE3 from rejecting the route due to AS-Path loop prevention.

Thus, this statement is true.

D . 'If no additional action is taken, CE3 discards the route.' ( True)

By default, CE3 will discard the route because of BGP loop prevention (same AS in the AS_PATH).

To allow CE3 to receive the route, the allowas-in or substitute-as command must be configured on PE2.

Thus, this statement is true.

3. Evaluating the Answer Choices

Option

Correct?

Reasoning

A

False

Applying SoO does not directly enable CE3 to receive the route.

B

False

If both CE1 and CE2 have the same SoO value, CE2 will reject the route.

C

True

Substitute-AS allows CE3 to accept the route by modifying the AS-Path.

D

True

Without additional configuration, CE3 will discard the route due to AS-Path loop prevention.

Correct Answe r : A and B are false.

Final Conclusion:

SoO prevents routing loops in MPLS VPN multi-homing.

CE2 will reject the route if it has the same SoO as CE1.

CE3 requires the substitute-as or allowas-in command to accept the route.

Thus, statements A and B are false.

HCIP-Datacom-Advanced Routing & Switching Technology V1.0 -- BGP SoO and AS-Path Loop Prevention

Huawei Official HCIP-Datacom Study Guide -- MPLS VPN Route Control

Huawei Documentation on BGP SoO and AS_PATH Filtering

Answer : C

Comprehensive and Detailed In-Depth

Understanding OSPFv3 LSA Types

OSPFv3 uses different LSA types than OSPFv2, with some being similar in function:

Link-LSA (Type 8): Generated by every router on a link to advertise link-local IPv6 information.

Intra-Area-Prefix-LSA (Type 9): Advertises IPv6 prefixes within an area.

Network-LSA (Type 2): Generated only by the Designated Router (DR) to advertise information about all routers on a multi-access network.

Inter-Area-Prefix-LSA (Type 3): Advertises network prefixes between OSPF areas (generated by ABRs).

Route Distribution Analysis:

HCIP-Datacom-Advanced Routing & Switching Technology V1.0 -- OSPFv3 LSA Types and Multi-Area Behavior

Huawei Official HCIP-Datacom Study Guide -- OSPFv3 Stub Areas and LSA Advertisements

Huawei Documentation on OSPFv3 DR/BDR Roles and LSA Generation

Answer : B

Comprehensive and Detailed In-Depth

The clock timezone command only affects the displayed time on the device and does not impact routing protocol operations.

Dynamic routing protocols such as OSPF, IS-IS, BGP, and EIGRP rely on timers, authentication, and correct network configurations, but they do not require the same time zone settings.

Potential issues with different time zones:

Log timestamps may be inconsistent, making troubleshooting harder.

Time-sensitive features like NTP synchronization might be affected.

But different time zones will not prevent dynamic routing neighbor relationships.

Reference: HCIP-Datacom Advanced Routing & Switching Technology -- System Time Configuration & Routing Protocols