サンプル問題 1： The undo command can be used in the CLI of a Huawei device to restore default settings, disable functions, or delete configurations. Which of the following are correct undo commands? (Select all that apply)
B: [HUAWEI] interface GE 1/0/1 [HUAWEI-GE1/0/1] ip address 10.12.1.1 24 [HUAWEI-GE1/0/1] undo ip address
C: [HUAWEI] interface GE 1/0/1 [HUAWEI-GE1/0/1] undo portswitch [HUAWEI-GE1/0/1]
D: [HUAWEI] sysname TEST [TEST] undo sysname [HUAWEI]
正解：B, C, D
Explanation: On Huawei devices, the undo command is used to remove a previously applied configuration, disable a function, or restore a parameter to its default state. In option B, undo ip address is a valid interface-view command that removes the IP address configured on the interface. In option C, undo portswitch is also a valid interface command on switch interfaces that converts a Layer 2 interface into a Layer 3 interface when supported by the device. In option D, undo sysname restores the device name to the default hostname, which is valid in system view. Option A is incorrect because system-view is a command used to enter system view from user view, but undo system-view is not a valid command for exiting that view. Exiting system view is done with commands such as quit, return, or by using shortcut keys. This question checks the understanding that undo only applies to configurable features and parameters, not to view-switching commands in the CLI hierarchy
サンプル問題 2： You can enter a question mark (?) in the CLI of a Huawei switch to obtain online help. Which of the following statements is true about the meaning of in the output of the command sysname SW1?
A: There are too many parameters in that position.
B: There is no keyword or parameter in that position.
C: The entered keywords are incorrect.
D: The command is incomplete.
正解：B
Explanation: In the Huawei command-line interface, the question mark? provides real-time command help based on the current input. When the output shows, it means that the command can end at that point by pressing Enter. In other words, there is no additional keyword or parameter required in that position. Therefore, option B is correct. In the example sysname SW1?, the device interprets SW1 as a complete and valid hostname parameter for the sysname command. Since nothing else is required after the hostname, the CLI displays to indicate command completion is allowed. This behavior is common in Huawei devices and is important for daily operation and troubleshooting because it helps engineers understand whether a command is complete, whether more arguments are needed, or whether optional parameters are available. Options about incorrect keywords or incomplete commands do not apply here, because the entered command syntax is already valid. Understanding <cr> is a basic but important CLI skill in HCIA-Datacom operations.
サンプル問題 3： Four links between two switches establish an Eth-Trunk in manual mode, and the bandwidth of each link is 1 Gbit/s. One of the links fails. Which of the following statements are true about this scenario? (Select all that apply)
A: The Eth-Trunk interfaces on the switches are still in the Up state.
B: The available link bandwidth between the switches is 3 Gbit/s.
C: The service traffic originally carried by the faulty link stops being forwarded by the switches until the faulty link recovers.
D: All TCP sessions established over the Eth-Trunk are immediately interrupted and re-established.
正解：A, B
Explanation: 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.
