H12-821_V1.0 Exam Dumps - HCIP-Datacom-Core Technology V1.0

Inter-area route calculation in OSPF involves Summary LSAs (Type 3) for summarizing routes across areas and ASBR Summary LSAs (Type 4) for locating ASBRs. While Router LSAs and Network LSAs describe the internal structure of an area, they do not directly participate in inter-area route calculation. Thus, the statement that only Router, Network, and Summary LSAs are involved is false ​.

Comprehensive and Detailed In-Depth Explanation:

SSH (Secure Shell)providessecure remote loginanddata encryptionover insecure networks.

A. TRUE→ SSH requiresuser authenticationbefore access is granted.

B. TRUE→ Enabling SSH openslistening ports, which could bescanned by attackers. Proper security measures (e.g., disabling unused SSH access) are recommended.

C. TRUE→ ACLs can be applied toVTY (Virtual Terminal) linesto restrict SSH access based onIP addresses.

D. FALSE→ The default SSH server port is22, not 23. Port23is used forTelnet, which isless securethan SSH.

📖Reference:Huawei HCIA-Datacom Study Guide, SSH Configuration and Security Measures.

Comprehensive and Detailed Step-by-Step Explanation:

Definition of Link Aggregation:

Link aggregation combines multiple physical links into a single logical link to improve bandwidth and reliability.

Advantages of Link Aggregation:

Load Balancing (A):Traffic is distributed across all aggregated links to improve performance.

Improved Reliability (B):If one link fails, traffic is rerouted through other links.

Increased Link Bandwidth (C):Bandwidth is effectively the sum of all aggregated links.

Incorrect Option:

Route Backup (D):Route backup is a feature of routing protocols, not link aggregation.

Comprehensive and Detailed Step-by-Step Explanation:

VRRP Virtual MAC Address Format:

The VRRP virtual MAC address is generated using the format:0000-5e00-01XX, whereXXrepresents the VRID in hexadecimal.

Calculation:

VRID = 1 → Hexadecimal =01.

Virtual MAC =0000-5e00-0101.

Correct Option:

C (0000-5e00-0101).

ï‚· Inasynchronous mode, BFD control packets are exchanged periodically to detect faults.

ï‚· Indemand mode, once the session is established, BFD stops sending periodic control packets and relies on external mechanisms to verify connectivity.

 Asynchronous mode is the most commonly used mode. However, the Echo function is supported in asynchronous mode, making Option B incorrect ​.

In Layer 3 roaming scenarios, STAs (stations) remain on different subnets before and after roaming. To ensure that user traffic reaches the original subnet, it must be tunneled back over a CAPWAP tunnel. This technique prevents disruptions in communication and enables seamless roaming. Huawei’s Layer 3 roaming design guidelines emphasize the use of CAPWAP tunnels for user traffic forwarding ​.

In OSPF,Database Description (DD) packetsare used during the database synchronization process. In the first DD packet a router sends during neighbor establishment, three control bits are set:

I bit (Initial)= 1 → This indicates that the DD packet is the first in the sequence.

M bit (More)= 1 → This means more DD packets will follow.

MS bit (Master/Slave)= 1 → Set by the router assuming the master role in the exchange process.

Setting all three bits to 1 is a standard part of the DD exchange initiation.

Reference from Huawei HCIP-Datacom-Core Technology Study Guide:

“In the initial DD packet, the I, M, and MS bits are set to 1 by the master router initiating database exchange.”

(Chapter: OSPF Operation Mechanism – Section: Neighbor State Machine)

GRE (Generic Routing Encapsulation) is not a Layer 2 VPN technology. Instead, it is a Layer 3 tunneling protocol used to encapsulate a wide variety of network layer protocols inside point-to-point connections. GRE is commonly used for creating VPN tunnels across IP networks,allowing for the transport of various types of payloads. This misunderstanding about GRE being a Layer 2 technology contradicts its definition and typical application ​.