Pass the Huawei HCIP-Datacom H12-821_V1.0 Questions and answers with ExamsMirror

 R3, as the DIS in the Level-2 domain, periodically sends Complete Sequence Number Protocol Data Units (CSNPs) to ensure LSDB synchronization among Level-2 routers.

 R1 and R2 are in a Level-1 domain, and IS-IS requires the receiving router (R2) to acknowledge an LSP from R1 by sending a Partial Sequence Number Protocol Data Unit (PSNP).

 IS-IS LSPs in a broadcast network are sent using multicast, not unicast, making option C incorrect.

 For Level-2 LSPs, acknowledgments are not provided using PSNP by R3; CSNPs are sufficient for synchronization ​.

Application Specific Packet Filtering (ASPF) is a feature that allows the firewall to understand and handle multi-channel protocols such as FTP, H.323, and SIP. ASPF inspects the control channel to dynamically create temporary rules for the data channels, enabling the firewall to secure and manage complex application protocols. This feature ensures that appropriate security policies are applied to these multi-channel applications ​.

A is correct – Removing unused accounts helps minimize the risk surface .

B is false – Email is not a secure method for transferring sensitive information like passwords, even if encrypted.

C is correct – Unique administrator accounts help with accountability and tracking.

D is false – Long-term password validity reduces security. Passwords should be rotated regularly.

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

“To secure admin access, avoid account sharing, delete inactive users, and periodically update credentials through secure channels.”

(Chapter: Device Security – Section: Account Management)

Comprehensive and Detailed Step-by-Step Explanation:

IGMPv1 Querier Selection:

In IGMPv1, there is no built-in querier election mechanism. Querier selection depends on the multicast routing protocol (e.g., PIM).

IGMPv2 and IGMPv3 Querier Selection:

In IGMPv2 and IGMPv3, the router interface with the largest IP address in the multicast group is selected as the querier.

Correct Statement:

The statement accurately describes the querier selection mechanisms in IGMP versions.

Multi-channel protocols such as H.323 and FTP use separate control and data channels. H.323 uses different channels for call signaling and media streaming, while FTP uses a control channel for commands and a data channel for file transfers. Telnet and SMTP are single-channel protocols ​.

 ACL Modification

Named ACLs can be modified after their creation. Unlike numbered ACLs, named ACLs provide greater flexibility for editing individual rules without deleting the entire ACL.

Therefore, the statement is incorrect.

 HCIP-Datacom-Core Reference

The flexibility and editability of named ACLs are discussed in the ACL configuration sections​​.

All four are valid reasons why IKE (Internet Key Exchange) negotiation might not be triggered:

A – Security policy mismatches can block data flows , preventing IPsec from initiating.

B – If the route to the peer is unreachable , no packets can reach the tunnel interface, and IKE will not start.

C – If the IPsec policy is not bound to the correct interface , no protection is triggered.

D – If the ACL does not match the actual traffic , the flow will bypass IPsec.

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

“Common causes of IKE negotiation failure include incorrect ACLs, misapplied policies, unreachable peers, and misconfigured security zones.”

(Chapter: VPN Technologies – Section: IPsec Troubleshooting)

 Transitive vs. Non-Transitive Attributes

The Community attribute is a transitive optional attribute , meaning that if a router receives a route with this attribute and does not understand its purpose, the router retains and propagates it to other peers.

Other options, such as AS_Path and MED, are well-defined mandatory or optional attributes with specific purposes.

 HCIP-Datacom-Core Reference

The behavior of optional transitive attributes is detailed in the BGP protocol and attribute chapters​​.

When a stack splits, the MAC addresses of the newly formed stacks do not change immediately. Instead, they retain their original MAC addresses until new ones are reassigned during topology updates. This delayed update prevents immediate conflicts and allows MAD (Multiple Active Detection) to handle any resulting issues ​.

 In asynchronous mode , BFD control packets are exchanged periodically to detect faults.

 In demand 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 ​.