Huawei H12-821_V1.0 HCIP-Datacom-Core Technology V1.0 Exam Practice Test

Answer : C

Understanding the Network Setup:

The OSPF network consists of three areas (Area 1, Area 0, and Area 2).

The server's subnet 192.168.1.0/24 is directly connected to R1 and imported into OSPF using the command:

import-route direct type 1 cost 2

The type 1 specifies the route as an OSPF Type 1 external route, meaning both the external cost and the internal OSPF cost will be included when calculating the total cost.

The external cost specified for the imported route is 2.

Cost Calculation to R2:

The interfaces between the routers are GE interfaces, and the default cost for GE interfaces is 1.

The path from R2 to the server goes through the following hops:

R2 R1: Cost = 1 (intra-area link).

R1 Server: External cost = 2 (specified in the import-route command).

Total cost to R2:

Intra-area cost (1) + External cost (2) = 3

Verification of Each Option:

Option A (2): Incorrect. This only accounts for the external cost, ignoring the internal OSPF cost.

Option B (4): Incorrect. This overestimates the cost by adding an extra hop.

Option C (3): Correct. The total cost is 3 (1 for the intra-area link + 2 for the external cost).

Option D (1): Incorrect. This ignores the external cost of the imported route.

HCIA-Datacom Study Guide, Chapter: OSPF Route Types and Cost Calculation

Huawei OSPF Cost Configuration Details

Answer : B

OSPF routers refresh and flood LSAs in the Link-State Database (LSDB) every 30 minutes by default to maintain topology consistency. OSPF does not rely on TCP; it uses its own acknowledgment mechanism. It also uses the Dijkstra algorithm, not Bellman-Ford. The flooding interval for LSU packets is shorter, typically 5 seconds .

Answer : C

For first-time configuration of a newly purchased network device, administrators typically use the console port. This direct connection is secure and independent of network configuration, making it suitable for initial setups. Telnet, SNMP, or FTP require prior IP configuration, which is not feasible during the initial setup phase .

Answer : A

RST BPDU Handling

On an RSTP network, if a port receives an RST BPDU and determines its own buffered BPDU is superior, it discards the received BPDU without responding. This ensures stability and proper convergence in the network.

HCIP-Datacom-Core Reference

BPDU handling is described in the RSTP operation chapters.

Answer : B, D

The prefix list permits the prefix 1.1.1.1/24 with a mask length greater than or equal to /26 and less than or equal to /32. This means only prefixes with the base 1.1.1.1 and mask lengths between /26 and /32 will be permitted. Routes like 1.1.1.2/16 and 1.1.1.1/24 do not meet the mask length criteria, so they will be denied. Conversely, routes like 1.1.1.1/26 and 1.1.1.1/32 satisfy the condition and will be permitted .

Answer : A, B, C, D

OSPF Area Design and Loop Prevention:

OSPF uses a hierarchical structure with areas to improve scalability and efficiency. Area 0, the backbone area, plays a crucial role in ensuring loop-free route distribution between areas. The following mechanisms are key to preventing routing loops:

Strict adherence to hierarchical area design.

Prohibition of direct inter-area route exchanges between non-backbone areas.

Analysis of Each Statement:

A . Inter-area routes cannot be directly transmitted between non-backbone areas.

This statement is TRUE. OSPF mandates that all inter-area routing must pass through Area 0. Direct inter-area route exchanges between two non-backbone areas are not allowed to prevent loops.

B . All non-backbone areas must be directly connected to area 0.

This statement is TRUE. OSPF requires every non-backbone area to connect directly to Area 0 to facilitate loop-free inter-area routing. Virtual links may be configured in exceptional cases where direct connection is not possible.

C . Inter-area routes need to be forwarded through area 0.

This statement is TRUE. All inter-area traffic must traverse Area 0 to ensure hierarchical routing and loop prevention. This rule is a core design principle of OSPF.

D . An ABR cannot inject Type 3 LSAs that describe routes to a network segment in an area back to the same area.

This statement is TRUE. OSPF explicitly prohibits an ABR from injecting Type 3 LSAs describing a route into the same area where the route originates. This mechanism prevents routing loops within an area.

Conclusion:

All options (A, B, C, D) are correct. OSPF enforces a robust loop prevention mechanism through hierarchical routing, mandatory traversal via Area 0, and strict rules on LSA propagation by ABRs. This ensures reliable and loop-free inter-area routing in OSPF networks.

Answer : A

The native AC (Access Controller) function in Huawei's agile switches enables wired and wireless convergence. This integration allows the agile switch to act as both a wired network switch and a wireless controller, managing all traffic centrally. This architecture simplifies network management and improves efficiency, making the statement true .