H12-811_V2.0 Reviews Questions

When a switch receives an untagged frame from a user host on an access interface , it associates that frame with the VLAN configured on the interface. In this scenario, PC1 and PC2 are in VLAN 10, and GE1/0/2 is an access interface in VLAN 10. After SW1 receives the frame from PC1, it internally associates the frame with VLAN 10 , so option A is correct in the practical VLAN-processing sense used in HCIA-Datacom questions.

When the frame is forwarded out an access interface toward PC2, the switch sends it without a VLAN tag , because end hosts normally do not process 802.1Q tags. Therefore, option D is correct. Option B is incorrect because both hosts are in the same VLAN and can communicate normally; SW1 does not discard the return traffic for that reason. Option C is not correct in the standard VLAN switching model used by Huawei training, because the switch performs forwarding based on VLAN membership and internally processes the frame as belonging to VLAN 10. This question mainly checks understanding of access/trunk behavior and tag handling on ingress and egress.

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The correct statements are B and C . Option B is true because general-purpose computing data center networks focus heavily on stability, reliability, service continuity, and flexible VM deployment. Technologies such as M-LAG improve gateway and uplink redundancy and support fast failover, while VXLAN enables large-scale Layer 2 extension for VM mobility and resource flexibility.

Option C is also true because intelligent computing networks, especially those serving AI training and distributed GPU clusters, require an extremely low-loss or lossless forwarding environment. Technologies such as PFC and ECN are standard methods used to build such networks and reduce congestion-related packet loss. Option A is not selected because modern general-purpose data center networks do not necessarily require the traditional core-aggregation-access three-layer architecture ; contemporary data centers commonly use leaf-spine fabrics instead. Option D is not selected because although intelligent computing networks do require ultra-low latency and RoCE helps reduce network communication latency, the wording about “latency of data transmission within a compute node” is not the standard network-side requirement emphasized in HCIA-Datacom. The focus is mainly on inter-node network transport efficiency and lossless forwarding.

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On a non-root bridge, the root port is the port that receives the best BPDU toward the root bridge. STP selects the root port by comparing several parameters in order. The first important parameter is the root path cost (RPC) , so option B is correct. If multiple ports have the same RPC, the switch then compares the bridge ID (BID) of the upstream device sending the BPDU, making option C correct. If those are still equal, the switch compares the port ID (PID) of the upstream sending port, so option D is also correct.

If all of those values remain identical from the switch’s perspective, the device can finally compare the local port ID to determine which local interface becomes the root port, so option A is also correct. HCIA-Datacom teaches this comparison logic as part of STP election rules. The process ensures deterministic selection of a single root port on every non-root switch. Understanding the comparison sequence is essential for predicting STP topology behavior and for influencing port roles through path cost tuning or bridge-priority adjustments during campus network design and troubleshooting.

In an Eth-Trunk working in manual mode , multiple physical member links are bundled into one logical interface to provide higher bandwidth and link redundancy. If one of four 1 Gbit/s member links fails, the Eth-Trunk does not go down as long as at least one valid member link remains active. Therefore, statement A is correct. Since one link has failed and three member links remain available, the total available bandwidth becomes 3 Gbit/s , so statement B is also correct.

Statement C is incorrect because the traffic originally hashed to the failed link is not permanently stopped. Instead, after the link failure is detected, traffic is redistributed across the remaining active member links according to the trunk load-balancing mechanism. Statement D is also incorrect because Eth-Trunk provides link-level redundancy. Existing upper-layer sessions such as TCP are not necessarily interrupted and re-established simply because one member link fails. HCIA-Datacom emphasizes that Eth-Trunk improves reliability and bandwidth utilization by allowing traffic to continue across surviving links when a single member fails. This is one of the main advantages of link aggregation in campus and data center switching networks.

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