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

The set-overload command places the router into an overload state, indicating to neighbors that the router should not be used as a transit node. This is mainly used during bootup to stabilize the routing environment.

By default, this overload state lasts for 600 seconds (10 minutes). After this time, the router automatically clears the overload state, assuming no manual configuration changes were made.

✅ Official Reference from Huawei:

" By default, a router remains in the overload state for 600 seconds after the IS-IS process restarts. During this period, the router does not function as a transit node in the SPF calculation. "

— [Huawei HCIA-Datacom Study Guide – IS-IS Protocol Chapter]

Restrict → Discards the packets that trigger static MAC address flapping and reports an alarm.

Protect → Discards the packets that trigger static MAC address flapping only and does not report an alarm.

Shutdown → Sets the interface state to error-down and reports an alarm.

Comprehensive and Detailed In-Depth Explanation:

1. Understanding Port Security Modes

Port security is used to control access on a switch port based on MAC addresses. If a MAC address violation occurs (e.g., static MAC address flapping), the switch can take different actions based on the configured security mode.

Security Mode

Description

Restrict

Drops the violating packets and logs the violation by generating an alarm.

Protect

Drops the violating packets but does not generate an alarm.

Shutdown

Places the interface into error-disabled (error-down) state and logs an alarm.

2. Matching Each Security Mode with Its Operation

Protect Mode:

The switch drops the packets from the unauthorized MAC address.

No alarm is generated or logged.

Correct Mapping: " Discards the packets that trigger static MAC address flapping only and does not report an alarm. "

Restrict Mode:

The switch drops the packets from the unauthorized MAC address.

An alarm is generated and logged in the system.

Correct Mapping: " Discards the packets that trigger static MAC address flapping and reports an alarm. "

Shutdown Mode:

The switch shuts down the interface by placing it into the error-down state.

An alarm is generated and logged.

Correct Mapping: " Sets the interface state to error-down and reports an alarm. "

1. Understanding Router-LSAs in OSPFv3

Router-LSA (Type 1 LSA) is generated by every OSPFv3 router to describe its own links and connected networks within the same area.

Each router in an OSPF area generates exactly one Router-LSA to advertise its own topology information.

Router-LSAs are flooded throughout the area but do not cross area boundaries.

2. Analyzing the Given OSPFv3 Network

The topology consists of three routers: R1, R2, and R3, all connected in OSPFv3 Area 0.

Since all three routers participate in OSPFv3, each router generates its own Router-LSA (Type 1 LSA).

R2, as an OSPF router, will have its own Router-LSA and also receive the Router-LSAs from R1 and R3.

3. Counting the Number of Router-LSAs in R2’s LSDB

R1 generates 1 Router-LSA (for itself).

R2 generates 1 Router-LSA (for itself).

R3 generates 1 Router-LSA (for itself).

Total Router-LSAs in R2’s LSDB = 3 (one from each router).

Final Answer:

Answer: 3

HCIP-Datacom-Advanced Routing & Switching Technology References:

OSPFv3 LSA Types and Their Roles

Understanding Router-LSA (Type 1) and Its Function in LSDB

Comprehensive and Detailed In-Depth Explanation:

Understanding OSPF Areas and Route Propagation in the Network:

OSPF Area Types in the Question:

Area 0 (Backbone Area): Connects all areas and distributes routing information.

Area 1 (Standard Area): Regular OSPF area that can receive and forward external routes.

Area 2 (Totally NSSA - Totally Not-So-Stubby Area):

Does not allow external routes except for a default route injected by the ABR.

Area 3 (NSSA - Not-So-Stubby Area):

Allows external routes as Type 7 LSAs but does not accept Type 5 LSAs.

How External Routes Are Advertised in This Scenario:

R5 (in Area 3) imports 10.0.5.5/32 as an external route into OSPF.

Since Area 3 is an NSSA, the external route is advertised as a Type 7 LSA (not Type 5).

The ABR (R1) converts the Type 7 LSA into a Type 5 LSA and advertises it into Area 0.

Once in Area 0, this Type 5 LSA can be distributed to other areas except totally stubby or totally NSSA areas.

Route Distribution Analysis:

R5 (Area 3) → R1 (Area 0, ABR):

R5 generates a Type 7 LSA for 10.0.5.5/32.

R1 (ABR) converts this Type 7 LSA into a Type 5 LSA and injects it into Area 0.

R2 (Area 0) → R3 (Area 0):

Since Area 0 allows external Type 5 LSAs, R2 and R3 receive 10.0.5.5/32.✅ R2 and R3 have the route.

R6 (Area 1) → Connected to Area 0:

Area 1 is a common area, meaning it can receive external Type 5 LSAs.✅ R6 has the route.

R4 (Area 2 - Totally NSSA):

Totally NSSA areas do NOT accept Type 5 or Type 7 LSAs.

Instead, they receive only a default route from the ABR (R3).

Since R4 does not receive external routes explicitly, it does NOT have 10.0.5.5/32.❌ R4 does NOT have the route.

Final Conclusion:

✅ R2, R3, and R6 have the route 10.0.5.5/32.

❌ R4 does not have the route because Area 2 is a Totally NSSA and only gets a default route.

Thus, the correct answer is:

✅ R2, R3, and R6 have the route 10.0.5.5/32 in their routing tables.

This statement is false. Time zone configuration using the clock timezone command affects only the local display of time on a device (e.g., logs, timestamps), and has no effect on dynamic routing protocol operation.

OSPF, BGP, IS-IS, and other routing protocols do not rely on time synchronization or time zone matching between devices to establish neighbor relationships.

Even if devices are in different time zones, they can still form adjacencies as long as IP connectivity and protocol parameters (e.g., hello/dead intervals, authentication) are correctly configured.

✅ Official Reference from Huawei:

" The clock timezone command sets the local time zone for display purposes. It does not affect protocol operations or neighbor relationships. "

— [Huawei HCIA-Datacom Certification Guide – System Management Section]

OSPFv3 AS-External-LSAs advertise external IPv6 routing information across permitted OSPF areas.

The displayed LSA identifies the originating router as 10.0.3.3, confirming option C. The Route Tag field contains the value 1, confirming option B.

The LSA specifies Metric Type 2 with a metric of 1. For an E2 external route, the advertised external metric remains the primary route metric, while the internal cost to the ASBR can be used for tie-breaking. Therefore, option A describes the E2 metric behaviour.

Option D is not established by the exhibit. Although NSSA Type 7 LSAs can be translated into AS-External-LSAs by an ABR, the displayed Type 5 LSA does not independently demonstrate that translation occurred.

Consequently, the statements supported by the LSA are A, B, and C.

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

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R4 is an ASBR inside Area 1, which is configured as a totally NSSA. When R4 imports 10.0.4.4/32, it originates a Type 7 NSSA LSA within Area 1. Therefore, option A is incorrect: a totally NSSA can contain Type 7 LSAs for external routes imported locally.

Type 7 LSAs have area-local flooding scope. R1 and R3, acting as NSSA ABRs, do not flood the original Type 7 LSA into Area 0 or Area 2. Instead, the selected translator converts the external information into a Type 5 LSA. The configured asbr-summary 10.0.4.0 255.255.255.0 command causes the translated external information to be advertised as the summarized 10.0.4.0/24 Type 5 LSA.

Area 2 is a common area and therefore cannot contain Type 7 LSAs. Option C is incorrect because Area 0 receives the translated Type 5 external LSA. Option D is not a valid conclusion because common and backbone areas support Type 4 LSAs, and asbr-summary does not suppress that LSA type. Huawei’s LSA support table explicitly identifies Type 7 as supported only in NSSA and totally NSSA areas. Huawei OSPF documentation

The statement is false due to a contradiction.

Sticky MAC addresses are not aged out automatically. Once a MAC address is converted to sticky, it is bound to the port and does not age out like dynamic MAC addresses unless manually cleared or the configuration is removed.

If the goal is to allow MAC entries to age out when users change frequently, dynamic MAC addresses (not sticky) should be used.

✅ Official Reference from Huawei:

" Sticky MAC addresses are retained across restarts and do not age out. To allow MAC addresses to time out and be relearned, do not use sticky configuration. "

— [Huawei HCIA-Datacom Certification Guide – Port Security Section]